P: Inconsistent Shadow Direction in Lightroom Classic Slideshow Module (Export vs. Preview)

The shadows in the slideshow module are not working as expected for me.   LR Classic 14.2.  Sequoia 15.3.2, 5K iMac (Intel).   When I create a slide show with a background and the make a shadow with the photos and use an angle of -45, the shadow moves towards the top of screen.   However when I export that slide to a jpeg the shadow is projected towards the bottom of the screen.   Finally when I use a text overlay with shadows of the text, the -45 degree angle makes a shadow falling towards the bottom of the screen and that behavoir is consistent on the export.   I have attached a screenshot from the creation of the slide and the slide output.

Screenshot from LR Classic

Export of jpeg from Slideshow mode