I’m having an issue where masked objects quickly become unstable.

What happens:

I select my clip in the timeline, use the object selection tool, create my mask & then assign it to opacity in the left side effects panel.

• Mask works normally at first
• After a few playthroughs it starts flickering
• Flickering gets worse
• Eventually the mask disappears completely

This is happening to most masked objects, not just one.

In one case, I tried deleting and re-adding masks before export:

• Worked temporarily but only 1 of 2 masks showed up in the final export

Additional context:

• Some clips are inside nested sequences
• Issue occurs in both playback and export
• Already tried clearing cache and re-rendering

I’ve attached a short clip showing the behavior.

❓ Questions:

1. Is this a known issue with masking (especially tracked/object masks)?
2. Can nesting cause masks to fail or disappear like this?
3. What is the most reliable workflow to prevent masks from breaking or missing in export?