Unfortunately I am still having issues with Aqara motion sensrors on FW5 as well (RC57 by now). A while ago my zigbee network was extremely unstable. I even swapped 10 Osram bulbs for Aqara tunable ones (hoping they would play well with the sensors), and while stability has improved a lot I still have not had more than one day without Zigbee issues!
Motion detection of some Aqara sensors will just stop working while others are fine, some bulbs do not turn on when motion is detected (or with extreme delays), and bulbs do not turn off any more. I also had cases where I could no longer successfully pair sensors at all until a reboot. This all happens even with devices connected directly to Homey, and I have tried everything from restart app/restart Homey/PTP (even did a Zigbee reset last week). When things go wrong I eventually end up having to pair a couple of sensors again. I have sent many support requests and diags dumps to Athom but no concrete confirmation that any issue was found so far.
The Nodes view looks fine as far as I can tell, and this also confirms I have more then enough bulbs/plugs that are used as zigbee router. I would also love to hear if something is wrong with my devices, network, the RC or the drivers. It looks like a combination of the RC + Aqara driver. 
[Update] Seems the issue was more related to the Homey zigbee chip reaching its limit with 50 connected devices. Switched to Conbee 2 + HomeyCONZ App, all zigbee issues are gone.
