Catalina Calendar & Photos

HI! I recently upgraded from High Sierra to Catalina, but I have some problems (of course I didn't have these problems with High Sierra!)

Calendar - I use Calendar a lot and everyday I change, move and add a lot of events and memos. However it often happens that (these are examples ...)

(1) -after creating a new event(or after making a few changes)- it suddenly loses what I wrote (in notes, the new date or hour etc etc) (sometimes -though not always- I can cope with this malfunction "playing" with command+Z).

OR

(2) after moving an event from a date to another one (different from the day where I created the event) I can't find this event in the new location but I can find it again in the previous date (that is I can't move it). I have to do the changes more than one time only and I succeed in my plannig... at last!

I'm trying to face this awkward behaviour saving Calendar ASAP and very often (that is closing the app and reopening), but it's a hard way to manage the app.

Anyway what I mean is that Calendar worries me because I think it can be no more reliable (that is... may happen that I'm not always be aware of the Calendar changes ... so what's happening if I miss appointments or don't find my memos?)

Photos - The situation with Photos is simpler. Photos crashes. If I'm working hard with this app (searching, moving and removing items, for instance) suddenly crashes. Afterwards I re-open the app and I can work, maybe without any crash for a while... or for a long time, but Photos crashes almost two or three times a day.

Well I hope that with the others Apps I'll have no surprises, but I'm really worried.

Why does it happen?

I read that Catalina is a stable macOs ...and I don't play with the system and I don't install unsafe software.

Thanks to everybody for your suggestions.

MacBook Pro 15" mid 2014 - 2,8 GHz Intel Core i7 quad-core - RAM 16 GB

- MacOS 10.15.7 - Macuser since 1984

Calendar version 11.0

Photos version 5.0