Hmm,

For me I also lose connections on wifi but for me the messages in the log just say deassociated.

Now I did some further digging but to my surprise some devices act different, some auto disconnect for power saving, other ones can directly disconnect when theres no dhcp, and some get connection but dont show a error it has no internet.

I think something happens when flint renews their dhcp lease, it might give a wrong dhcp server, or it might just shortly have no dhcp at all.

Could you try and test what happens if you force your dhcp?

You find it in luci->network->interfaces->your wifi interface->then dhcp, for vlans this worked for me, for wifi not but you could give this a try.

If that doesn’t work, what happens if you go use purely static routes and have no dhcp at all?

I couldn’t test this further since I think my phone does it out of energy saving, I wish there was a standard how devices act that would make diagnosing alot easier.

Edit

Just to add aswell, it could be part of rebind protection and double nat please test with it off aswell if it was enabled.