web login method: Access Forbidden, Invalid Request

[openbugbot]

The server:
docker image of nextcloud 16.01
https://github.com/nextcloud/docker
docker pull was used sqlite is used

The iOS client:
iOS 2.23.6.15

When use web login method after clicking Grant Access button get a screen that says:

Access Forbidden,
Invalid Request

The login works fine when reverting back to old login method

[andreaswilli]

I'm getting the same message when trying to log in from iOS to Nextcloud behind Nginx Proxy Manager. When I access Nextcloud by local IP directly it works.

I'm fairly new to Nextcloud and Nginx Proxy Manager so it's possible that I misconfigured something. Any help is appreciated.

[andreaswilli]

I was able to solve my issue. In admin settings, Nextcloud displayed a warning (something about insecure urls) and after following the instructions in the docs, login also works when using the proxy.