P: Photos don't show up in grid view on startup

I sometimes apply a filter combination of Flagged/Unflagged (so excluding rejected pics) and a red color label, using a custom color label set. When this filter was active on quitting Lightroom, the grid view stays empty when I start up Lightroom and only after doing some action (switching to a different folder and going back, changing the filter and undo the change) the photos show up like they should. If I also filter on the white color label (which isn't included in the custom color label set) the photos show up immediately on opening Lightroom.

Library filter options: Lock Filters and Remember Each Source's Filter Separately are active. Lightroom version 7.3.1 on macOS High Sierra 10.13.4.