[Error replicating branch on sync process - Source branch has two heads]

I opened Plastic again now and it wasn't able to locate my repository. I uninstalled it.

[Error replicating branch on sync process - Source branch has two heads]

I created my repository a few hours ago and I'm trying to sync it from local to cloud for the first time (I'm using distributed version control). When I first tried to push the outgoing changes, the Sync failed because I had to first pull the incoming changes. So I successfully did that, and then I tried pushing again. This time, however, the branch replication failed because "The source branch has two heads", and I should "Merge from cs:af2f3159... [name continues] to br:/main to unify the heads". The problem is that I can't seem to find this "cs:af2f3159" etc. head anywhere to merge it with br:/main. I already tried to merge changesets both from the Changesets screen and from the Branch Explorer, but I'm always told that "The merge search has finished; merge destination already contains source changes", with no conflicts to solve or changes to apply.

This is how my my Branch Explorer looks like:

Any help would be appreciated.