Ubuntu 20.04 built-in display scale option doesn't work on all aplication except the system bars and pointer

Question

It happened when I unpluged a external 4k monitor. Rebooting and seting xrandr are useless.

screenshot:

• 100% scaling: window big, side bar normal

• 200% scaling: both too big

• xrandr --output eDP-1 --scale 2x2: window back to normal scale but the pointer is scaled 200% too and reset back after restart.