Companion APP not showing TOTP (2FA) after system update

Hi, after some troubleshooting I need some extra pair of eyes.. help?

My setup is simple.
Internet - Cloud flare - ISP - My router - traefik - Home Assistant host

I have run this setup for years without network issues.

Today I updated both OS and Core:

Installation method
Home Assistant OS
Core
2026.8.1
Supervisor
2026.07.5
Operating System
18.2
Frontend
20260729.6
Companion app
2026.6.5-full (22884)

After the update, everything seemed to work (I was connected through browser on public endpoint).
But, the companion app stopped working. Nothing loaded, 60s timeout.

I cleared the cache, and even wiped the data.
I got the login screen, and it seemed ok.
But, TOTP box didn’t show up. Just a button saying start over, taking me back to step 0.

On browser everything works. With different computers on different networks (tested with VPN just to be sure)

I temporary disabled 2FA for my user so I could authenticate with companion app and it worked, afterwards I re-enabled it since the session was created successful.

Any hints are more than welcome .

Thank you
Sam