Underscan not working

[ChannelJuanNews]

I ran the following command to see a list of my displays

$ display_manager.py show

display "main":
resolution:     2560x1440
refresh rate:   0
HiDPI:          True
rotation:       0
brightness:     0.84
underscan:      0.00

display "ext0":
resolution:     1080x1920
refresh rate:   60
HiDPI:          False
rotation:       90
underscan:      1.00

Then I ran this command to underscan the external display

display_manager.py underscan 0.7 ext0

It gave me no error, so I assumed everything worked okay. After running that command, I restarted my computer and low and behold, the underscan stayed exactly the same... Am I doing something wrong???

OUTPUT of show exactly the same

$ display_manager.py show

display "main":
resolution:     2560x1440
refresh rate:   0
HiDPI:          True
rotation:       0
brightness:     0.84
underscan:      0.00

display "ext0":
resolution:     1080x1920
refresh rate:   60
HiDPI:          False
rotation:       90
underscan:      1.00

[uurazzle]

Hi @ChannelJuanNews,

Sorry, our team has been very busy, but we will review your issue and reply back with details when we have time.

To provide your details, which macOS version are you using? Is this Apple hardware or a Hackintosh system?