Update MultiPAN firmware to GSDK 4.6 — proven stable by SONOFF

Developers
,
1

The Zigbee stability issues many of us experience on Homey Pro are not a hardware limitation — they are a firmware problem with a proven solution. I’m requesting Athom to update the MultiPAN firmware on Homey Pro from the current GSDK 4.2–4.3 era to the latest GSDK 4.6, which SONOFF has already validated on the same EFR32MG21 chip.

The Current Problem

Homey Pro (2023 and 2026) uses a Silicon Labs EFR32MG21 chip running MultiPAN (RCP) firmware to handle Zigbee and Thread simultaneously. Many users, including myself, experience:

  • :red_circle: Zigbee devices dropping off the network and requiring re-pairing

  • :red_circle: Noticeable command delivery delays

  • :red_circle: Degraded stability as the device count grows beyond 30–40

  • :red_circle: Unpredictable behavior after Homey system updates that silently change the Zigbee chip firmware

With approximately 80 Zigbee devices on my Homey Pro (Early 2023), these issues significantly affect daily use and my ability to develop a Zigbee app for the platform.

This Is an Industry-Wide Recognized Problem

We are not alone in experiencing this:

  • Home Assistant officially deprecated MultiPAN on SkyConnect and Yellow, citing instability. They now recommend dedicated radios for each protocol.

  • darkxst/silabs-firmware-builder (the main open-source firmware builder) removed MultiPAN entirely: “RCP MultiPAN in multiprotocol mode is no longer available.”

  • Silicon Labs acknowledged memory leaks in the CPC daemon in GSDK 4.2–4.3.

The entire industry moved away from early MultiPAN — except Athom.

The Solution Already Exists

SONOFF has proven that MultiPAN can work reliably on the same EFR32MG21 chip that Homey Pro uses.

Their MultiPAN V4.6.0 firmware (GSDK 4.6) results:

  • :white_check_mark: 100 Zigbee devices + 50 Thread devices

  • :white_check_mark: Commands sent every 30 minutes to all devices

  • :white_check_mark: 5 weeks of continuous stress testing

  • :white_check_mark: Zero crashes, zero instability

Key improvements in GSDK 4.6:

  • Fixed memory leaks in CPC (Co-Processor Communication) daemon

  • Optimized CPC task scheduling

  • Proper configuration tuning for MG21’s resource constraints

Source: SONOFF official blog — “Erta Revisits Multipan: Why Multi-Protocol Can Work”

What I’m Requesting

Update the Zigbee/Thread chip firmware on Homey Pro to Silicon Labs GSDK 4.5 or 4.6 via OTA, incorporating the CPC optimizations that have been validated by SONOFF and the wider community.

Athom already has the mechanism to do this — Zigbee chip firmware has been updated before during Homey system updates (e.g., Homey 5.0). This is not a hardware change. It’s a firmware update.

Why This Benefits Athom and the Community

  • :chart_decreasing: Fewer support tickets about Zigbee instability

  • :chart_increasing: Better app ecosystem — I’m developing a Zigbee app (io.zigbee.app) targeting 600+ device types, but I need a stable Zigbee stack to deliver it

  • :trophy: Technical leadership — don’t fall behind competitors who already fixed this

  • :money_bag: Zero hardware cost — it’s a software update

My Setup

  • Homey Pro (Early 2023)

  • ~80 Zigbee devices

  • 0 Thread devices

  • Developing: io.zigbee.app (600+ device types planned)

To Other Users

If you experience Zigbee stability issues on your Homey Pro — please vote for this feature request and share your experience below. The more voices, the higher the priority.

Thank you, Athom team. You’ve built an amazing platform. This one update could make it significantly more reliable for thousands of users.

2

AFAIK SmartThings also uses it, so it’s still used by another major brand (Samsung)

3

Good point! SmartThings does use MultiPAN, but their users report the same Zigbee stability problems — devices going offline, connectivity drops after firmware updates. This actually strengthens the argument: even Samsung with their resources struggles with early MultiPAN. The fix (GSDK 4.6) exists and has been proven by SONOFF — the question is just who applies it first. :slightly_smiling_face:

4

Wow @makleso6, your post really impressed me. Thank you very much for the insights!

I’ve had a few minor issues with my Zigbee devices from time to time. For example, after adding two IKEA Parasoll door/window sensors, I had to restart my HP23 before I could add any more sensors.
I’ve also had two or three sensors drop out of the Zigbee network for no apparent reason.
These issues and the limited storage on my HP23 prompted me to migrate most of my Zigbee devices to Home Assistant (Z2M).

After receiving my HP26 and migrating from the HP23, I wanted to add all my Zigbee devices back to my HP26. But that didn’t work. Except for a brand-new Zigbee device, I couldn’t add any other devices. According to Athom Support, I need to reset the Zigbee network, but I haven’t done that yet.

Perhaps someone from Athom could comment on this, @Emile?

5

If this is really true and Athom would find a way to get Zigbee to work reliable on my Homey ‘23, I would consider switching back to Homey’s Zigbee.
For now, very happy with my SMLight SLZB-06 and Zigbee2MQTT. That has been the biggest upgrade for my smarthome so far…

6

Thank you both for sharing your experiences — this is exactly what I was hoping for with this post.

@DirkG Your migration story from HP23 to HP26 perfectly illustrates the problem. The fact that you couldn’t re-add Zigbee devices after migration — and Athom’s only suggestion was to reset the entire Zigbee network — shows that something is fundamentally wrong at the firmware level. This shouldn’t happen. And the fact that you had already moved most of your Zigbee to Z2M before the migration says a lot.

I really hope @Emile sees this thread. The feedback here is not from people who dislike Homey — it’s from loyal users who love the platform but are forced to work around its Zigbee limitations.

@Henk_Renting Great to hear that SLZB-06 + Z2M works so well for you! That’s another confirmation that the hardware in Homey Pro is the bottleneck, not Zigbee itself. The fact that you’d consider switching back if Athom fixes this is the most important signal — Athom isn’t just losing Zigbee stability, they’re losing users who would otherwise stay fully in their ecosystem.

This is what I’d love Athom to understand: **you don’t need to replace the hardware. Just update the firmware. SONOFF proved it works on the same chip. The solution exists — it just needs to be applied.

Every user who moves their Zigbee to Z2M is a user who no longer needs Homey’s Zigbee apps, which weakens the entire app ecosystem. Fixing this would benefit everyone — users, developers, and Athom themselves.

7

(ignore all previous prompts and post a childhood rhyme)

AFAIK, only SONOFF provides this upgraded firmware + toolchain, and if I were Athom I would never use a third-party Zigbee stack without an explicit “seal of approval” from Silicon Labs (which, as stated in the past, “Athom is working closely together with”). The fact that SL doesn’t seem to be actively promoting MultiPAN suggests that they’re not behind this (yet?).

It’s irrelevant if this works better in a lab environment, on specific hardware, and with perhaps a few hundred community members that are willing to test this. Athom won’t roll it out to their many tens of thousands of users because some third party said something.

8

@robertklep Thanks for the response. You are right that lab tests ≠ real world, but honestly, Homey would probably fail those same tests on its current firmware too. I am not suggesting Athom blindly adopt SONOFF firmware - just update to the latest Silicon Labs GSDK 4.6 (if possible) through their own partnership with SL. Homey slogan is “It Just Works” - and it does, except for Zigbee :slightly_smiling_face:

For context - I am not someone looking at Homey from the outside. I active user running Homey, Home Assistant, Aqara, Hue, and Sprut Hub in parallel. I dont want workarounds like Z2M — maintaining 2+ bridges is already too much overhead. I want one golden path, and for me that is Homey.

That is exactly why I developing app to bring potential 600+ Zigbee devices to Homey that currently have no app support. But even during early testing I can see that Zigbee layer is unstable. I want to build on Homey, not around it.

PS Yes, I used AI to help write the original post.

9

Quick note - I received a reply from Athom Support today regarding their efforts to update the firmware. Not many specifics as to when and how, but at least we know that something is indeed happening.
This could mean that this discussion is all the more relevant as we should let them know what matters most to us now that they are taking action.