Update:
After followign [this recent thread]( Editor keeps crashing constantly page-2) that was reporting an issue similar to mine (the biggest difference was that the issue was happening on the editor instead of on the build in their case) I’ve been able to resolve the issue;
It seems in fact that the problem was a Unity bug and it was fixed in the latest Unity version a few days ago (2021.3.28).
So far neither me nor the players that were reporting bugs could reach more crashes, so I would say it’s finally fixed!