I'm making a Flow that - among other things - copies a file from folder to a newly created folder.
But Flow keeps adding a trailing backslash for som reason:

Note how there is no trailing backslash in Destination Folder (Destinationsfolder) but still a backslash is inserted.
Full error message:
How do I avoid the trailing backslash? I've tried inserting a forward slash (/) at the end, but just ends up with both "/\".
I've checked, and there are no invisible characters or anything at the end of the string.