Project manager shows duplicated sequences

I think something broke in the deepest darkest parts of the project file.

I just tested something, which worked:
Create a new project, saved it in a different location, copied everything in the old project (project panel>ctrl-a>copy) and pested it in the new project.
Then, I closed the old project, and I went to the projet manager in tje new project, and there was a clean list of sequences.

I'm having the same issue, but with all sequences.
Each sequence is listed 7 times.

Really weird. If you highlight the sequence in the Project Panel before going into project manager the sequence should have a check mark telling you that it is the only one selected. May not answer your question but this will confirm that only that sequence will be collected in Project Manager.