Can't log in behind a proxy with Wizard V2 - Stuck on web page "Grant Access"


I just have configured nextcloud to run behind a proxy. I can authenticate and use it through mobile app and web access.
The only issue I´m getting now is the grant access to wizard desktop app, it gets stuck on the web page “Grant access”.

I tried to found some related issues, here, but nothing similar I found.

Any help would be helpful.