Screen goes dim after turning monitor off and on again

[menac1ty]

AMD RX 570, Asus VX239H running on latest drivers
I'm using CRU and the patch to get to 1080p@76Hz no problem, no frame skipping, using reduced blanking settings.
The problem is that whenever my computer goes to sleep, or if I manually turn off my monitor and turn it back on again, the display is super dim. It get's fixed once I restart the video driver or restart the PC. It doesn't matter what refresh rate; I've tried with stock 60Hz and 76Hz.All the same. The only "fix" is to to "reset-all.exe" and not use CRU at all.
What is wrong here?
One more thing: when I turn my monitor on, right before it comes on I can hear the windows "device unplugged" sound.

[Nearox]

I am encountering the same problem. Been using CRU for years on my monitor (LG 29UM59-p) to increase the freesync range from 45-75 to 40-75 hz. Working perfectly.

However, recently I tried to set it to 39 - 75hz. Ever since, whenever the screen goes off or the computer reboots, the screen is very dimmed. I have tried going back to 40-75hz but to no avail.

To fix it temporarily, I can either or use restart64.exe or reset the monitor itself via its own built-in menu. But this only works until next time the PC is rebooted.

I have even reinstalled windows 10, cleaned all drivers numerous times but I cannot seem to fix the issue.

Interestingly, the screen is totally fine until the moment windows loads something (I assume monitor driver/settings from registry) and then it goes dimmed (not dark).

In fact, the only way it got fixed permanently was by reinstalling windows 10 and by not using CR. But then my freesync range got stuck at 45-75. I could reboot as much as I want without issue. But as soon as I did CRU, the problem began again.

@Toasty do you think you could help to find a solution?

[ToastyX]

It's an AMD driver bug. I don't know of a workaround because any EDID override will trigger the bug regardless of what changes. I don't know what circumstances trigger the bug because not everyone has this problem. I thought it was related to 10 bpc color, but neither of those monitors have 10 bpc color listed in the specs. I think the last driver that didn't have this bug is 19.11.2.

[Nearox]

(12-03-2020 02:03 AM)ToastyX Wrote:  It's an AMD driver bug. I don't know of a workaround because any EDID override will trigger the bug regardless of what changes. I don't know what circumstances trigger the bug because not everyone has this problem. I thought it was related to 10 bpc color, but neither of those monitors have 10 bpc color listed in the specs. I think the last driver that didn't have this bug is 19.11.2.

Thank you very much for your reply and insight.

I do know that AMD is misreading Front Porch since I used CRU. Maybe this info is useful to you?

[Nearox]

Hello,

I would just like to say I fixed the issue.

I simply made a new custom resolution in the AMD control panel that was tuned by pixel clock of .100 or .200 mhz lower. everything else the same.

After applying it, the screen got its brightness back immediately.
For a few times I had to do it again at reboot of windows, having to change the value of the pixel clock bya different one than the previous.

Now I reboot without issue. Not sure if it is because I found the exact right pixel clock.