Z2M Multiple Devices Suddenly Gone Offline

Hi, I’m using a ZBDongle-E (FW: 6.10.3.0) as coordinator for my Zigbee network. It has been working great now for almost a year, coordinating a network of 50+ devices, but yesterday suddenly 15-20 devices just “fell out”, apparently for no reason. They are reporting as Offline and the log shows multiple “Failed to Ping” warnings.

Failed to ping 'Bathroom Floor Thermostat' (attempt 1/1, Read 0x1fff00020000001b/1 genBasic(["zclVersion"], {"sendWhen":"immediate","timeout":10000,"disableResponse":false,"disableRecovery":true,"disableDefaultResponse":true,"direction":0,"srcEndpoint":null,"reservedBits":0,"manufacturerCode":null,"transactionSequenceNumber":null,"writeUndiv":false}) failed (Timeout - 46565 - 1 - 88 - 0 - 1 after 10000ms))`

I have many different types of devices both powered and with battery and it seem random which devices has gone offline as there are some devices of each type.

I did update the Z2M version the other day to 1.33.2-1 the other day, but everything seemed to be working fine after that until this happened. I have tried restarting Z2M serveral times and I have also rolled back the HA VM with the Z2M addon so that the Z2M version is back to 1.30.3-1, but I still have the same issue.

I don’t have much experience troubleshooting network issues and could use som input on how to proceed and get mye devices back online and what might have caused this.

Edit: It also seems I am not able to re-pair devices. I tried re-pairing a device that has gone offline and it just resulted in it disappearing from the Z2M network altogether. Wouldn’t that indicate that there was some connection even though it was showing as unavailable and not responding? Why else would it disappear from the network when I reset the device without doing anything in Z2M?

You are probably better of posting/asking in the Zigbee2MQTT’s own community on GitHub here → https://github.com/Koenkk/zigbee2mqtt/discussions/

But be sure to have already followed the tips here → Guide for Zigbee interference avoidance and network range/coverage optimization