Sonoff ZigBee sensors disconncts

I am having bad experience with sonoff ZigBee sensors, and I’m trying to see if I miss something.
I have to HA setups (in my apartment, and in my parents’).
The first with Conbee and ZHA.
Mine with Sky connect and ZHA.
All aqara sensors are working perfectly in both setups. Sonoff temp sensors - one with drained battery after a few weeks. One keeps disconnecting.
Sonoff temp display - I re-adds it every few days, and it stops updating. The display keeps updating but HA not.
It’s a small space so no need for ZigBee routers, I use USB extension to limit interference.
It sonoff bad with ZigBee? Can I do something to improve it?

There are many things that can cause sensors to fall off the mesh.

From personal experience and from posts by other users on the forum, Sonoff’s sensors can be prone to falling off when their batteries are low and when there aren’t enough routers in the mesh or the routers are poorly placed.

There are many tips and trick on making sure your network isn’t the issue here:
The Home Assistant Cookbook - Index.