2 unusual puzzles

1. Vertical sync disappeared from the desktop and from programs, including metro applications.
even the transparent selection rectangle breaks.
everything is fine in the toy. vsync works.
Google does not shine with the mind in this matter.

2. when you enable 10-bit color in win10 in 2 metro applications (store and win + g overlay), the animation disappears when the cursor is hovered over the tiles and the inscriptions on the tiles under the cursor disappear.
how can you fix it? any ideas?