Yes, it’s a known issue that was previously fixed, but the code was changed a bit in order to support the latest mpv version and the bug was reintroduced.
The “No Sound Fix (libmpv)” add-on was a bit old and I updated it to the latest mpv version, it should fix the cropping issue if it happens near the end of the audio file, the mpv developers fixed it in mpv v0.37.
But the add-on is no longer needed, the latest Anki version was recently released and the issue with the “pause” button will be fixed.