Hello, I had the same message as you (INVALID FRAME (854): ‘{“type”:“auth_invalid”,“message”:"Auth message incorrectly formatted: extra keys not allowed @ data[‘dst’]}’") with a Raspberry Pi HA installation (dockerized).
I eventually found a solution, but the issue was not related to the dockerization. It turns out that, in addition to my internet box, I have a Deco Wi-Fi mesh router that was creating a dedicated subnet mask (the Raspberry Pi was on 192.168.1.X and the Shelly on 192.168.68.X). Switching the Deco from router mode to access point mode instantly solved the problem.
It’s very specific, but I hope this can help others!