After removing a shared group from the project, users still have access to the project

I had a group of developers that I wanted to give access to multiple projects. So I created a group and added 3 devs to it.

I then went to the Members settings in a particular project and shared that project with the group. I did not add that project to the group, just the share option. I did this for multiple projects.

Then my work with those devs was done, so I deleted the group and I don’t see that group or any of the members in my shared projects. But they still have access to it. I also see their names pop up when I’m assigning issues for those projects.

How can I remove them?

UPDATE:
I reproduced the same thing with another gitlab account that I have. And the same thing happened. I can’t even leave the project. So that means I can’t ask those 3 devs to leave those projects either.

Is it happening on GitLab.com or your on-premise installation?
Are you still facing this issue?