I'm missing @mentions, sometimes they are not in my Inbox?
It's probably because you have changed this setting:
With this setting, whenever a conversation gets closed, it is removed from your Inbox, even when you were @mentioned. This setting only excludes conversations you are watching.
We consider this an advanced setting that can be useful in unusual cases. It’s mainly a way for people who get too many notifications to “aggressively” clean their Inbox when coworkers close conversations. Most users should leave this setting to the Keep in my Inbox default.