I have a working installation of Nextcloud 15 (in a docker container, behind a nginx reverse proxy over https), and the iOS app has no pb connecting to it, as well as the web interface.
When running the connection wizard from the Windows 10 Installer, I enter my login/password and the wizard then asks to grant access to Mozilla/5.0. I grant the access, but from there, it loops back to the login page “Connect to your account”, and then again to grant access, and so on for ever.
I have no idea what is going on. Could it be related to the fact that my nextcloud container listens to port 80, and “sees” https only through the reverse proxy?
NB: the alternative “log in using app token”, once provided with a valid token obtained from the settings of the web interface, fails an returns a 405 error.