Hi @NicoleKuyten ,
Could you please share the detailed flow steps?
In general, the issue you described could be due to the lack of extension for file name. I made a test on my side, but can't reproduce your issue, the flow shown as below works properly..
Please refer to the following steps and try to see if your problem can be fixed. If you still have problems, try adding the extension '.docx' after the name.

Hope this helps.
Sik