When I open the updater app, it tells me that I have the latest version installed. I have 2020.4.8.
When I do Help - Check for updates, it correctly tells me that 2020.4.12 is available, but when I click on "Download now" I get the same message about having the latest version installed from the updater app.
Looks like bug #01142 in the release notes. (https://www.photools.com/release-notes/)
Ah.
I ran into that updating from .8 as well. Easy workaround is to go to the customer portal & manually download. You are going to have to uninstall .8 before installing .10 or .12 anyway.