The Plakoto thing is funny, it actually looks like a piece disappears. But if you play on, the piece reappears when the trapping piece moves away. I guess it is (yet another) problem with the special image files used in Plakoto.

The problem used to be that some of those image files were missing. That meant that you had to set the game settings for backgammon type games to the smaller version - if you didn't, sometimes some tiles of the plakoto board would not show at all. That's probably why you were told to change the settings. But it seems that now some image files have been swapped around somehow, the result being that some trapped pieces don't show on the screen. This should be fixed.