OS V3.13 > 4.11 update broke zigbee2mqtt

Configuration
1

System working fine until updated from 3.13 to 4.11 system boots but zigbee2mqtt can nolonger see the MQTT server. I was using ‘mqtt://hassio.local’, so changed this to fixed IP address, which overcome that problem. This allowed me to control the hive lights (got their own hub) but not the ikea ones or sonof tasmota flashed (through CC2531 USB)

Tried a restore but this doesn’t restore the OS version only core. Any ideas how I can revert to an earlier OS version to get this working again?

Core: 0.110.4
OS: was 3.13 now 4.11
zigbee2mqtt: 1.14.1
Mosquitto broker: 5.1

2

Managed to download the 3.13 build & restore to get back to working system. Tried the 4.12 update but the same problem. Dont want to be stuck on the older OS version indefinatley, any ideas? Which logs should I capture, etc. thanks