Weird computer monitor issue

Hi, people smarter than I am.  Thanks for stopping by.

I have 2 old 32" Samsung monitors - LS32F351FUNXZA

As far as I can tell from the tags they have identical revision info.  Build dates within 2 months of each other, albeit in 2016.

One is dying, with scattered horizontal white lines that flicker across it.  That's old news and not the issue.  Other than that it works great in native 1200x1920, when hooked to my wife's laptop.

The other one is NOT dying, but when it's hooked to the same laptop with the same HDMI cable and same power supply, it's crammed into a weird letterbox format that's non-native so it's horribly pixelated and unreadable.

When I look at display settings, the second monitor only offers me 1080x1920 - not even an option for the 1200x1920.

If it means anything, the laptop is a little enterprise-grade Dell, less than 6 months old.  HDMI connection through a Lightning dongle... but again, exactly same connection as the one that works.

Anybody have suggestions?  Thanks again.

The only 2 possibilities I can think of are different firmware revisions on the monitor, or an issue with the settings on the computer - which you should be able to fix with these steps:

https://winaero.com/clear-reset-external-display-cache-windows-10/

In reply to GameboyRMH :

Excellent, thank you.  I was planning to try updating the firmware on the monitors (if that can even be done) to see if that helped.  I am pretty certain it's never been done to either one.

My thought is maybe toward the cache issue, though, because I believe both monitors run fine connected to other computers.  At least both had been in regular service before I appropriated them for home office use.

Thanks again.

I verified that the weird monitor works fine on a different laptop.

I didn't find any way to directly update the firmware on these monitors, but I was able to download a driver for them from Samsung.  I'll try installing that on DW's work laptop (if we are allowed) and also try clearing the display cache as suggested (again, of we are allowed).

Figured it out. Refresh rate for that particular monitor on her computer was set to 59.940 Hz.

Set it to 60 Hz and it snapped right into shape.

Thanks, Gameboy.