Good news, it’s working now! I thought by updating to WC Vendors Pro, the Vendor Dashboard would be replaced automatically. That’s not the case since the screen looked the same and there were options like I saw in pictures for the Pro version.
Vendor Dashboard is a page tied to the free version. What I had to do was to edit my menu to link to the Pro Dashboard page. Now Add Product works. Clicking on a product to edit says “No Permission.” That happens with UM deactivated as well. I will create a different thread for that in the Pro forum.
Since the Pro Dashboard works with Ultimate Member (UM), I would encourage WC Vendors to review the code for Vendor Dashboard and see why that doesn’t work with UM. This issue has dated back to 2015 and hasn’t been fixed. I hope this saves someone a few hours!