Mask of Smartfilter embedded in SmartObject doesnt Work in 20.0.1

I've got a SmartObject. I edit its content which is another SmartObject. There I do some adjustments with SmartFilters and edit the mask. Save.
Back in the main document, after PS auto-refreshing the SmartObject's content, my adjustments are visible all over. The mask doesn't do it's job.
Still works as it should in the previous PS CC version