Downscaling within FCPX leaves edge bleed from clips below top one #443

Apple Feedback Assistant ID: FB21914564

DESCRIBE THE BUG:
We recently got flagged by our iTunes QC house that there's a 1 pixel edge in spots on our master. It happens any time a clip is over a bright clip, like a letterboxed black matte over footage. It's fine if the footage is not scaled down (or probably up too). It looks fine in FCP, but when you export you get a 1-pixel line around the edge that is a merge of the two layers.

TO REPRODUCE:
I went back through our masters to see when this started happing and it was between Jan and march of 2022. Before that we had no issues with it. I'm surprised this is the first time we got flagged.

EXPECTED BEHAVIOUR:
Should not bleed from the edges like that.

SCREENSHOTS:

SPECS:

• 2021 16-inch MacBook Pro (M1 Pro, 16GB RAM), 2020 MacMini (M1, 16GB RAM)
• macOS Sonoma 14.7.2
• Final Cut Pro 10.8.1

ADDITIONAL COMMENTS:
NA