**System Information**
Operating system: Windows 10
Graphics card: RTX 3060ti
**Blender Version**
Broken: 2.93 alpha as of the 24th of february
Worked: It's been like this since I used the VSE for the first time some versions ago, just haven't report it until now :)
**Short description of error**
When using some of the blending modes in the VSE the opacity slider won't do anything until you drag it all the way down to 0. The bug does not affect all Blending modes, for example Add, Multiply and Alpha Over works as intended, but Screen, Color Burn and Difference do not. I don't really see any pattern of which that works and don't.
**Exact steps for others to reproduce the error**
Go into the VSE, add and image at the bottom and some other on top, press N to access the side panel, change the blending mode of the top image to Screen and try to change the opacity.