Copy changes from one .fmf file to another?

Hello, so when I go to the "Database Changes", I can select some changes and under Edit>Copy(Databage Changes) I can --supposedly-- copy and paste them. But when I open my other .fmf file and go to "Database Changes", click on Edit>Paste, nothing happens. I tried reloading, saving as and reopening it, checking to see if it's under a different game database (which is not), even trying to select the same player to paste his changes. So I was wondering if there is a way to do that. Lemme know if you want t

Thanks in advance