[Flatpak] Online account doesn't appear in other apps
I am running an up-to-date Debian 10 (stable) system with the Gnome desktop environment, and on top of that I have install Evolution as a flatpak (from flathub). I have also installed Gnome Calendar as a flatpak. However, the caldav calendar associated with the account I have added to Evolution doesn't show up in Calendar. My account also doesn't show up in the Online Accounts system settings section.
This is unfortunate, as I believe that the only way to add a caldav calendar to Calendar is actually through Evolution (see e.g. this issue for Gnome Online Accounts).
I believe this is a regression and that it all used to work, but unfortunately I can't pin down during which update to which program it went wrong. I did try to downgrade to the Evolution 3.32 flatpak version, and that didn't solve the problem.
I suppose I could give up on the flatpak version of Evolution and just use the version in the Debian repository.