Double slashes in _pdata->{_url} when LLNG is OIDC RP

In our portal we have one LLNG (v2.0.13) as OIDC relying party to an external OIDC identity provider. A nextcloud is a OIDC relying party to our LLNG. (But it also affects SAML clients)

The portal url in the manager is https://login.example.com/

When a user opens https://nextcloud.example.com/ he will be later redirected to https://nextcloud.example.com//oauth2.

With the latest haproxy version and with http2-mode turned on, these double slashes throw an error.

As a quick fix, we turned http2-mode off in haproxy. The login to the nextcloud works again.

I tried to remove the slash in the portal url, but it was not successful. After saving the slash reappears.

I see two possible fixes:

1. Remove the slash here. This seems to work for me.
2. Remove the slash in the portal url. I am not sure, if this has side effects.