Duplicate entries when adding users through Modern Sharepoint 'Share' pop-out menu

We are seeing some strange behavior on some of our Modern Communication sites. When adding a user or a group with Read or Edit rights via the share button on the top of the page, we are seeing duplicate entries. See the image below for clarification.

 

So adding someone as read, also shows them as being able to edit, and vice versa. If we have a look at the underlying permission groups, 'Everyone' shows up correctly in the Read category. However, the ~30 users in the Members category that show up in the underlying group, are also not visible the share menu. 

 

Has anyone ever experienced something like this? This issue comes up twice, the other team and communication sites work just fine.