Since updating to version 13 ...
The entire LR interface will disappear for a second or two from my secondary screen if it's displaying the thumbnail grid while marking images with filters set. For example, filters are set to only show unflagged images. I mark an image rejected, it disappears from view, the grid changes and this causes the interface to disappear. It does not happen every time ... but at least half the time. Occurs, regardless of the type of filter enabled and in both Loupe and Develop modules. The issue does not hinder my workflow, but it is very annoying.
And possilby related ... the main LR window on my primary display automatically pushes the Mac OS window header out of view to where I can only see a few pixels of it running across the top of my screen. I am unable to access the close, minimize and expand buttons or move the window around. The perfect click-drag will pull it down, but it snaps right back.
I am using a fully spec'd Mac Studio M1 Max (Ventura 13.4), Studio Display (main) and Thunderbolt Display (secondary).