@mrlakes Recent versions of GNOME Online Accounts have generic CalDAV support; older ones can be made to work by choosing the Nextcloud option: https://semanticlab.net/sysadmin/linux/Gnome-Todo-and-CalDAV-servers/
@dos in the end it was easier to install evolution and sync my contacts and calendars via there. But then it also becomes available for Gnome Contacts and Gnome Calendars. So yeah, another workaround.
@dos Cool! Thanks! Looks like a change I can make