bgscan simple not always working

[Holger Schurig]

To know where "errors are detectable" we first must know what the
errors are. You cannot chase a vague idea, unfortunately.

Maybe "iw event -t" gives you a hint on what is going on ...   or a
full fledged packet trace, e.g. using wireshark, tshark or tcpdump. We
readers of the mailing list can only guess ... is it a bad SNR, is a
disassociation, is it the moon phase, is it the meshing algorithm?

If it's meshing related, you'd better ask at a better place, I'm not
sure if many people here do know this. I for example am a mesh-noob.

Please not that the "wpa_cli roam" feature is more or less a debugging
aid. For example, you must make sure by yourself that the bssid you
want to roam to is currently in the scan cache (as can be seen by "iw
scan dump"). It's not really meant for roaming, despite the name ...