From https://www.reddit.com/r/firefox/comments/ekak8g/weird_rendering_on_firefox_why/fdm5ryo/

User says it does not happen on Nightly.

Hi Asif, thanks for filing the bug with a screenshot and about:support.
We're asking reporters to enable extra driver validation and check if they get any errors the next time the issue reproduces:
https://bugzilla.mozilla.org/show_bug.cgi?id=1600357#c24
If you get a chance, would you mind recommending this to the original reporter and keep us posted? Thanks!

I am getting something very similar to this. I'm guessing it's the same issue, so I'm adding a screenshot and my about:support. I'll enable extra validation and report back if it reproduces. This only occurs about once a day.

1. A page will load correctly.
2. Randomly, random characters are missing. This includes page contents and even titles on tabs.
3. Minimizing and opening the entire Firefox window always fixes it immediately. Sometimes scrolling the page will fix it.

I have an NVidia RTX 2070. Hardware acceleration is enabled.

Ignore the previous upload. I accidentally uploaded the other users about:support

Occurred on https://www.synology.com/en-us/products/RS4017xs+

about_config with gfx.webrender.panic-on-gl-error enabled.

I noticed this time that moving over the corrupted areas with the cursor actually caused some of them to reload correctly. Scrolling also fixed some of the artifacts.

When you go to about:crashes - do you see anything listed there? Can you send us the contents of the latest crashes?

"No crash reports have been submitted."

I don't think it's actually crashing. The graphics are corrupted, but the next time they are updated by the system, they are corrected. So this bug is only apparent for a few seconds about once a day.

https://www.nvidia.com/en-us/geforce/news/game-ready-driver-for-division-2-warlords-of-new-york/

Nvidia GeForce 442.50 WHQL driver, latest driver if anyone wants to test.

I have been using Nightly for the last 15 days and this bug hasn't occurred. However, Nightly did crash earlier today and "webrender" is in the report title. I didn't notice this crash happen, but hopefully it's related to this bug. Pinging you back Jessie.

https://crash-stats.mozilla.org/report/index/644a95f7-968a-4532-8be7-b29590200228

Glenn, just pinging you to take a peak at this crash just in case: https://crash-stats.mozilla.org/report/index/644a95f7-968a-4532-8be7-b29590200228

I took a look at the crash logs, which contain:

|[G0][GFX1-]: GFX: AL_D3D11 abandoned sync (t=72069.4) |[G1][GFX1-]: GFX: RenderThread detected a device reset in WaitForGPU (t=72069.5) |[G2][GFX1-]: Failed to make render context current during destroying. (t=72073.8) |[G3][GFX1-]: Failed to get D3D11Device from EGLDisplay (t=72074.1) 

This suggests that Windows reset the driver, possibly due to a driver bug / crash, which seems unrelated to the ui-glitches stuff (this is good, since we believe it's fixed on nightly).

If you mean you didn't notice it at all during browsing, that seems like the GPU process crash handling working correctly. However, if you mean it was an explicit crash but you just didn't observe when it happened, maybe our device reset handling path has a bug in it?

Nightly had a notification around 6pm that a crash was not sent. The time on the crash was 4:29pm. I was at my computer at that time but didn't even notice Nightly crashing. I can't say if I was actively browsing with Nightly at that time.

If the bug is fixed on Nightly, I'll go back to using Firefox, so I can see if something in particular triggers it.

The suspected fix for this bug has shipped with Firefox 75 (bug 1617083) - we will reopen if this appears to happen again.

The user reports that they have not seen this issue in a while (at least since 75):

I can't recall the last time it's happened.