SUMMARY
when video grid is applied to a clip with alpha, at a non-zero value, it makes the alpha black. There's also any issues with alpha shapes + video grid but i'm not sure it's the exact same thing. I'm pretty sure it worked a few months ago though. (also sorry for the many reports i made recently)


STEPS TO REPRODUCE
1. Add a color clip to the background to see the alpha part
2. Add a png or make a title clip, or a color clip with alpha shapes, to track 2
3. Add video grid and change the values to whatever

OBSERVED RESULT
Alpha part becomes black

EXPECTED RESULT
Alpah stays transparent

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION