Poor performance in Calendar

Browser: Firefox 89.0.

When selecting the calendar tab, the browser becomes unresponsive. Only about 40 seconds later, the calendar finally loads. I used the calendar previously and I don’t remember it being that bad.

Taking a quick peek with the Firefox dev tools, Firefox gets completely locked up after a second or so, only does GC for about 40 seconds, and then recovers.

If you are interested, I can send you a performance profile.

FYI, I’ve just tested, without any delays in:

Firefox 89
Chrome 91.0.4472.77

I’ve tested this again on a new profile (should have done that in the first place). It still happens, although it only takes 35 seconds on a new profile until all calendars & appointments are loaded.

Thanks both for you comment on this issue. I wonder if this has anything to do with the number of items in the calendar? We are aware of some issues, but 40s is quite excessive.

Not sure about the total number of items, but within the view (month) I have about 5 items.