Directly in the line under your account, you can normally add a new account. Is there just a problem with the symbol missing? If you click in the white space, does anything happen?
No, unfortunately I can’t click anything in the white space below my account.
By the way my version is 3.10.0 (KDE) (flatpak).
Logging apparently doesn’t work as well. When I check the box to activate temporary logging and afterwards “Open folder”, nothing happens, and a /var/tmp/Nextcloud-logdir folder doesn’t exist.
EDIT: When running nextcloud via cli, the only output I get is qt.qpa.qgnomeplatform: Could not find color scheme "".