Mask from file with GL-transitions bug

The mask from file filter has a bug affecting HTML based GL transitions.

Using the 2 track method for the transitions, with the softness set above 1%, artifacts are visible at the transition edge in preview and export. I used 50% softness for the attached project.

Project illustrating the issue.

Mask from file with GL transitions.zip (3.4 MB)

This video was done with V 19.02.16. There are no artifacts in the transitions.

https://streamable.com/sjc1g

Sorry, but I am, going to pass to address this.

Confirmed. Quite noticeable: