Mac to Mac creates folders with Question mark

[Jo_Do]

Hello community,
Thank you very much for your help.
I didn't find anything about my problem here in the forum, so I ask you: I want to synchronize a MacBook with a MacMini. When I do this, some folders are always created with a question mark at the end. After synchronization I have two folders, one with and one without a question mark. At first I thought it might be a space at the end, but it's not. Next time FreeFileSync will create other folders with a question mark at the end. Do you have any advice?
the second thing that irritates me: I have a file "2_3 name". FreeFileSync turns it into "2:3 name". Do you know what is wrong here? Do I have to set something somewhere?
Kind regards and thank you
Jo