Windows 10: Firefox fonts "broken" but ONLY in Secondary display (duplicate main s

I had originally thought I had a problem with Firefox, Firefox fonts suddenly "broken", but it turns out that the problem shows up only on a secondary display but not on the primary display, which is a Lenovo 730 laptop. THERE IS NO ISSUE WITH WINDOWS OR ANY OTHER APPLICATION.

Details:
System is Lenovo730, 8550U CPU, 16 GB RAM, Intel UHD 620. Secondary display is Samsung 17", installed as a generic PnP monitor. Windows 10 64 Home with all patches applied. Firefox is 86.0.1. If you read through the earlier thread above, you will see that I used DDU to clean out the old GPU driver before installing the newest GPU driver which I downloaded from the Lenovo website.

If I look at the laptop screen, all the text in Firefox tabs looks normal. However, on the secondary display, the text looks like a lot of the pixels are missing or maybe they are light gray. My wife describes the appearance as "broken fonts."

Because I just looked at the laptop primary screen today, I had assumed that I had a Firefox issue. Now it's clear that Firefox works fine, but somehow there is an issue with displaying Firefox on the secondary display.

:)

 

Firefox fonts "broken" but ONLY in Secondary display (duplicate main s

I had originally thought I had a problem with Firefox, Firefox fonts suddenly "broken", but it turns out that the problem shows up only on a secondary display but not on the primary display, which is a Lenovo 730 laptop. THERE IS NO ISSUE WITH WINDOWS OR ANY OTHER APPLICATION.

Details:
System is Lenovo730, 8550U CPU, 16 GB RAM, Intel UHD 620. Secondary display is Samsung 17", installed as a generic PnP monitor. Windows 10 64 Home with all patches applied. Firefox is 86.0.1. If you read through the earlier thread above, you will see that I used DDU to clean out the old GPU driver before installing the newest GPU driver which I downloaded from the Lenovo website.

If I look at the laptop screen, all the text in Firefox tabs looks normal. However, on the secondary display, the text looks like a lot of the pixels are missing or maybe they are light gray. My wife describes the appearance as "broken fonts."

Because I just looked at the laptop primary screen today, I had assumed that I had a Firefox issue. Now it's clear that Firefox works fine, but somehow there is an issue with displaying Firefox on the secondary display.

 

Firefox fonts suddenly "broken"

After my wife did a Microsoft update this morning, she said that all the fonts in her Firefox browser now appear "broken," instead of "solid." I also noticed that the Windows buttons on the top right of the Firefox window also have some lines missing.

There are no issues with fonts in Edge or Windows, or any Windows application.

I tried to restore the Firefox profile from last night (last backup), but that didn't fix the issue. I played around with the font selection settings, but was unable to change from the default font to any other.

A Google search didn't turn up anything useful.

Any suggestions?

 

Blurry fonts on secondary extended display

i just bought a new LG 27UD58-B 27 inch/4K display and the resolution is gorgeous. however it recommends 150% scaling and the ST2210 Dell monitor recommends 100%. if I have both cards in the NVIDIA GTX 960 GPU and I scale the LG to 150% the Dell does the same and the font size is too blown up. If I try to have them scaled differently the ST2210 has blurry fonts and looks bad.

I have tried uninstalling NVIDIA software and reinstalling it. That didn't work. I have tried putting the ST2210 into the built in motherboard GPU and the LG in the NVIDIA...I then made the ST2210 the primary monitor and the LG the secondary monitor. This tends to work OK, but is hit and miss after restarts. I sometimes have to undo scaling and reassign the dpi% again to make it work. Also I'd like the primary taskbar to be on the LG...not the ST2210 . I can duplicate the taskbar on the secondary monitor, but the search option and the running indicators are not available on the duplicated taskbar. Any ideas? help??

Thanks
now I have the HDMI from the ST2210 to the motherboard GPU and the display port from the LG to the NVIDIA GTX 960