HA with ZHA keeps losing a signal repeater

I’ve migrated to ZHA and Sonoff USB Zigbee Plus P and so far the results have been good.

The biggest issue I’m facing is some devices like a signal repeater and ikea buttons are keep falling out of the network.

Especially the IKEA signal repeater is casing lots of trouble: I can add it easily but after some hours it looses a connection.

The repeater in question is located about 20m away from the route if measured in the indirect line of sight.

Anyone with ideas about the issue?
Perhaps some one can recommend a signal repeater?