I think Robert answered it already:
What you can do is to try to wake somebody from Athom up, and try to explain they probably do hit the rate limit, while probably the TP app of all app users combined make the rate limit getting triggered.
I’ve seen examples of apps which are bound to use an API with a general rate limit, which is, say 1000 a day.
Now, the more app users, the bigger the chance the limit gets hit.
Which is why the Hue app on Homey Bridge has poll intervals of an hour: all app instances share the same API key, and to prevent rate limiting by Signify Athom has had to severely limit the app (both in terms of status updates and the types of devices it supports).
FWIW I don’t think that’s the problem. Restarting the app immediately clears the issue and the device becomes useable again. I don’t think that would work if the limit was at the server end.
The Kasa phone app and the Alexa skill don’t have the same issue and, I can only guess, share the same API, pointing to an issue with the app - but still Athom.
I don’t think we can see the TP-Link Kasa app code? If we could, that would probably get us somewhere.
Andy
Fortunately, I only have 1 device - a 405 outdoor dimmer - which is supported by the community LAN version.
I was also hitting the rate limit with no clear cut time - as early as around 5 PM Eastern USA. Restarting the app did not clear it, neither did a repair of the device itself.
It would be nice to have the official app fixed, yet glad the community offering works well. Frankly, I purchased the Homey Pro to limit my non-LAN communications, so having a LAN based operation works better for me.
Good news everyone! We did some digging and found out that we where getting rate limited on the Authentication. This is something that we weren’t aware of since it wasn’t mentioned in the documentation. 
We got in contact with TP-Link and now they’ve doubled our rate limit, which hopefully should be enough! 
Happy to hear it this solves the problems for you guys!
Thanks for doing some digging! I’ll fire up one of my devices and do some testing, and report back.
I’m still getting it, saw that the app was updated so got a bit excited alas it was a new device.
Should it be working now or have they still to make the change?
Do we we need to repair?
Thanks
The rate limit has been adjusted on the server side, so no need for an update.
Is anyone else still encountering issues?
Yes still experienced it this morning. Do I need to uninstall the app and reinstall?
No. You can’t and don’t need to do anything for this fix
I will reach out to TP-Link to see if we can get a bit more bandwith! Keep y’all posted.
Hello Doekse
I just bought the Home Pro and am experiencing many issues (rate limit) with my TP-Link Kasa devices. Any solution?
Rate Limit error code 9a0ac2ab-ffb8-4027-aa87-1b1875065c6c
Thanks. German
Yes. Still have the problem. Still corrects with app restart. Still works with Kasa app. Still a big PINA
Seems to be working, since yesterday…
Still occuring but seems less then before
I just tried it, and it’s not working. I can’t rely on this technology erratically working. I think I’m going to return the Homey Pro to Amazon.
It has to do with the tp-link servers and not homey, if i were you i would invest in devices that work locally like zigbee or zwave.
I unfortunately haven’t heard from TP-Link about the issue, will nudge them tomorrow to see if we can increase the limit. Sorry for the inconvenience and keep y’all posted! 
Yes, but I will not change 24 switches at home from TP-link because Homey pro has compatibility issues. I still have my best hope on Homey, but it looks like it is not yet prepare for US market.
I’m in the same boat. About 36 TP-Links switches and daily errors. I love the switches but I wish they all worked locally with Homey.
