Multiple mask / black / transparency issue?

[shotcut]

You need to apply a workaround explained here:

Transparency lost when using add operation in mask, it's a bug?

Please improve the subject line. Otherwise, people (including developers) will probably overlook it as useless when scanning through the list in the category at a later time. We are rarely going to try to fix a problem as soon as we read about it. The problem is that Mask:Apply does not reset the alpha channel. That might be a feature for some, but a bug for others. You can see that by hiding V2 and adding a Alpha Channel: View after the Mask: Apply. The, track blender - by design - combines th…

Basically, after Mask: Apply add Alpha Channel: Adjust and set Mode to Reset. Then, click the Invert checkbox.

Alternatively, you can use Mask: Draw (Glaxnimate) to draw multiple shapes inside one mask, and then you do not need to reset the alpha channel (because the image before masking has no alpha channel, which implies opaque).