Hello,
maybe a bug, when I create a single clip with the Filter ‘Blend Mode’ on a videotrack in Mix Mode ‘Over’ and use different blendmodes for only that clip, then the entire videotrack affects to these blendmodes I only used for the clip.
Removing the clip removes not the previous effect in the videotrack, so I have to delete the track.
Please ensure you are not using a project file created with the 19.09 BETA version. That had a bug that sounds like this one, and wrong information was probably saved into the project as well. Otherwise, please provide steps or a screencast starting from a new project.
I was able to reproduce it by adding the Mask: Simple Shape filter to a clip on V2. An easier workaround than deleting the track is simply add the Blend Mode filter on the clips that are affected.
Actually, after I found the root cause, an even easier workaround is to go to track properties, and change Blend Mode to something else and then back to Over.