Ok I did something and it appears to have worked. I now see only the xlsx file uploaded into GDRIVE. Yay!
First of all “Attachment Details Mime Type” should be set to sheet not xlsx
Secondly, I don’t think resolution is ONLY turning the Zap ON, it involves selecting the right attachment from the detected attachment
I cycled through the different Attachments in the “Test trigger” step of the New Attachment Zap and after selecting “Attachment C”, the zap correctly filtered and uploaded the XLSX only
For whatever reason New Attachment Zap pulls a ton of Attachments when it tests.