FreeIPA LDAP is used by Gilab to login via HTTPS and using accounts with or without yubikey assigned to them can log in in just fine.
Git clone from shell with account NOT having yubikey mapped in LDAP works fine. (can clone, pull, push…)
Git clone from shell with account having yubikey mapped in LDAP does NOT work.
error: RPC failed; HTTP 401 curl 22 The requested URL returned error: 401
fatal: The remote end hung up unexpectedly
Two-factor authorization as such is NOT enabled in Gitlab. I would expect that password+otp combo for user is passed to LDAP for validation (just to clarify, yubikeys are mapped to ldap and not gitlab). All other apps to that and some reason Gitlab error out.