Can Nextcloud actually not merge two folders with the same name?

I recently got Nextcloud running as a Docker Container on my OMV server. Now I have stored quite some data on it. I realised that there are multiple folders with the same name in separate subfolders which I wanna merge (I got multiple “Music” folders and I want all the Music to be in one big folder). When I try to move one to the other, it shows an error, “target exists”. How can I go about merging them without having to manually compare all the contents? This really seems like a basic file feature that shouldnt be missing.