It’s most probably hardware related, not to the role it has (cloud extension / Pro sat / SHS sat).
It’s no hard limit, but just like the Pro 2016-2019 series, it’s recommended to not exceed 40 devices to avoid performance issues, but some have reported to use 70 zigbee devices perfectly on a Pro 2019.
It all depends on the used devices, how many different brands and interference.
Don’t build too big
Using Zigbee routers, you can create a stable Zigbee network of around 30-40 devices with Homey Bridge.
We do not recommend creating bigger Zigbee networks with your Homey. Adding more devices will put more stress on the network and might therefore negatively impact communication, reliability, and speed.
The limits of what is workable depend a lot on your specific situation.
If you notice Zigbee performance dropping after extending your network to a larger-than-recommended number of devices, you are probably pushing the limits of the Zigbee network in your home.
