XLIFF Manager for 2021 acting strangely

Sorry for all the error reports, but I guess it's the firefighting phase after a major version release...

The XLIFF Manager is acting strangely for Studio 2021, it worked beautifully for Studio 2019.

First of all, the icon in the appstore is somewhat random. Usually it has the "Record Source TU" icon for me, but now it has Modern MT:

Just now it disabled ModernMT and DeepL. (Uninstalling XLIFF Manager fixed it.) Somewhere there must be a bug or two...

Daniel