Device reported as having left the Zigbee network but is still working

I’ve been dealing with this issue for a long time now.

I was happy to see the relases of new firmware but the bad news is that firmware version 10.3.1 has not fixed the problem for me.

I just had two devices leaving the network. It mostly concerns philips hue devices ( RWL021 and SML001). Could the ‘philips hue without the bridge’ app be causing this? I have 4 routers in my network and no wifi channels are close to the zigbee channel. As reported before the devices are still active.