The calendar view seems to have a habit of jumping around when not prompted to do so.
As can be seen in the gifs (Sorry for the bad quality recordings) when toggling the Show/Hide Tasklist, the days shown in the calendar will shift. This can also happen when resizing the window.
I am guessing they are related, since it seems to be an issue with the infinite scroll introduced some time ago. Some artifact related to this can be seen when quickly switching forward and back in the view, the view jitters as if it had overshot the target.
I am on linux, so I have only been able to test the web version. More specifically Arch running Hyprland a Wayland compositor.
The jumping around is only on firefox. Chrome does not show this issue for me, however the small overshooting when going back and forth is there for both.
Will try to update when I get to use other systems.