Cannot get UniqueSuffix to work

Hi all, first post here -
I’m struggling with incrementing file names in the movie out TOP. I’ve turned on UniqueSuffix, and used a count CHOP to increment the N value. But no matter what I do, the file name doesn’t change with the N value. I feel like there’s something obvious I am missing, but can’t find it in the documentation. Do I need to put a python expression in the file name maybe?
I am in the newest version on macOS, but had the same issue in Windows. Really need for this project I am doing currently, so hope some of you can spot what I’ve missed!

Hi @arim_ne,

the default parameter value for the File parameter is actually an expression that contains a reference to the file suffix that includes the value of the N parameter. Does your name still contain the me.fileSuffix expression?

cheers
Markus