Is your suggestion for improvement related to a problem? Please describe.
When using the "merge duplicates" functionality, it is not possible to keep the assigned groups of two duplicates. I am only able to choose the groups of one of the entries. If I choose "keep merged entry", the entry is not assigned to any group afterwards.

Describe the solution you'd like
I would expect the "keep merged entry" function to assign the merged entry to all groups that any duplicated object was assigned to.

Additional context
I think it could also be up for discussion to merge the groups even when explicitly selecting one of the entries (i.e. "Keep left" or "Keep right") during merge. Personally, I cannot think of any use case that would need to merge an entry but not merge the groups.

I assume the the part of the code to fix this can be found here.