Users are not seeing the projects when assigned to them

Searching for help, I have upgraded the gitlab from ver10 to ver15 following the upgrade path. Everything went well. The next day a user called and told me that he is not seeing the project that was assigned to him by his manager. I rechecked with other users and had same issue. I have checked all services, DB upgrade was done and working with no fault or issue.

Can someone help in pointing me in the right direction on where to start looking as I couldn’t find anything related online .

PS: I’m new to gitlab, so please take it easy on me.

What do you mean?

Projects are not assigned to people, merge requests and issues (and probably more things that I didn’t think of). I haven’t used issues, but merge requests appear in the user’s To-Do list that is available with a click on the third icon from the right at the top (where the user stuff also is - on the right-most icon)