Are you using wayland? As far as I'm aware X11 can't handle different refresh rates for different monitors so it defaults to the lower one.

It looks like 1/4 of the games were released in the last 2 months(ish) lol:
-Baldur's Gate 3
-Dave the Diver
-Armored Core 6
-Holocure
-Remnant 2

If I'm counting it right, half of the games were released in the last 2 years

Pop just recently updated too, to Linux 6.4.6 and Mesa 23.1.3