MacBook Pro (mid 2012) 10.14.5
PM+ Version 6.0, build 3328 (da4b61a) and PM 6.0, build 3331 (38ae33c)
I see that the latest release fixed some of the slideshow issues, but just an FYI that there are still some bugs.
I usually run slideshows on a TV, so I hit the F key to get out of full-screen mode (1st screenshot) then drag the slideshow over to the TV, and hit F again (2nd screenshot).
In non-full-screen mode the text disappears, and when I go back to full-screen mode the text comes back but I get a tiny image.