And.... back to 384.13.
When reviewing the change log, version 384.14 says:
- UPDATED: RT-AC88U, RT-AC3100 to GPL 384_81351 and binary
blobs from 384_81116
Maybe this update broke AiMesh.
I've run a AC88U with two Lyra (with ethernet connection) without any problems with 384.13, and when I upgraded to 384.15 AiMesh got really unstable. Reverting back to 384.13 solved the issue.
I'm now testing the recent 384.16 firmware to check if AiMesh got fixed.