Photoshop 2020: Layer multiply transparency cancels in smart object when layer effect is applied to its group

Interesting bug.

I have a folder of some overlaying graphics that appear different as a smart object, than when entering it to edit.


What's happening is that when saved as a smart object (while appearing fine when editing) a colour overlay layer that is set to multiply at 50% opacity appears at 100% opacity when it's layer group has any effect applied to it. Applying effect directly works as intended.

I have worked around it in my file but I figured I'd report because it's rather peculiar.