Authenticating using webauthn on nextcloud ios

[caplam]

I discovered and installed authentik recently and enjoying it.
Big thanks for this app.
I use it for me and my relatives to access a dozen apps on my server.
So far (with the great help of cooptonian's video ) i managed to get everything working except one thing.

The most used app on my server is nextcloud and i login with authentik.
I started with simple login and added 2FA with TOTP. Then i added webauthn which is the issue here.
It works for login from a browser (safari, chrome, vivaldi, brave) from macos or windows. Keys are stored in apple passwords or bitwarden.
it also works from a browser from ios (vivaldi, safari).
The problem is with the ios app: as soon as the user select "use a security key" the passwordless flow starts and ends with "Authentication failure. Retry".
But it never gives the opportunity to select a key.
Does this behaviour sounds like a known issue ?

Login with authentik using password+totp from nexcloud app works too. The only problem here is when authentik asks for totp code i can't fill it from bitwarden or apple password as the windows close itself after a few seconds. I have to paste the code and it's then accepted.
For the context:
Authentik version: 2025.2.3 and certainly all 2025 versions (not tested on 2024 version)
Server Nextcloud aio: [Nextcloud Hub 9] (30.0.8)
Nextcloud ios: Nextcloud Hydrogen for ios 6.5.0.5
Nextcloud and Authentik are behind a reverse proxy (caddy as opnsense plugin).

Thanks for reading. Appreciate any help.
authentik nextcloud ios log.txt