AMD: gl driver not able to change screen refresh rate (only at 4K)

Description

When I use the "Screen Resolution" menu and select 3840x2160 (60 Hz), 3840x2160 (50 Hz), 3840x2160 (100 Hz), 3840x2160 (144 Hz) or any other refresh rate, RA does NOT change the refresh rate of the screen. It will always stay at the value I set in my desktop (120 Hz).
However when I select 1920x1080 (xyz Hz), then RA will change the refresh rate just fine.
I tried first going to 1920x1080 (50 Hz) to see if the refresh rate "sticks", but when I then go to 3840x2160 (50 Hz), then RA will go to 120 Hz.

With the d3d11 driver everything works as expected.

Expected behavior

RA should apply the selected refresh rate, no matter what resolution is selected.

Actual behavior

At 4K RA always sets 120 Hz or whatever I selected in Windows.

Steps to reproduce the bug

0. Run on an integrated or dedicated AMD GPU, does not occur on Intel or NVIDIA hardware
1. Select gl driver (restart RA if necessary)
2. Select "Screen Resolution" and choose one of the 4K modes and try different refresh rates
3. Check screen OSD if correct refresh rate was applied

Bisect Results

Also reproduces in RetroArch v1.9.0

Version/Commit

• RetroArch: v1.16.0

Environment information

For these experiments RA was set to exclusive fullscreen mode, VRR was disabled in Windows and in the AMD driver.

PCs where it occured:
PC 1:

• OS: Windows 11 23H2
• CPU: AMD Ryzen 7 5800X
• GPU: AMD Radeon RX 6800
• Screen: HP OPEM 27k (4K @ 144 Hz over DisplayPort)

PC 2: MINISFORUM Venus UM480 XT

• OS: Windows 11 22H2
• CPU: AMD Ryzen 7 4800H
• GPU: integrated AMD Radeon RX Vega 7 (max. 4K @ 60 Hz over HDMI 2.0)
• Screen: LG 49SM90007LA TV (max. 4K @ 120 Hz over HDMI 2.1)

PCs where everything worked:
PC 3: MSI Katana GF66 12UC [MS-1584]

• OS: Windows 11 22H2
• CPU: Intel Core i5-12500H
• GPU1: integrated Intel UHD graphics
• GPU2: GeForce RTX 3050
  I explicitly ran RetroArch seperately on both GPUs: No issues here with Intel and NVIDIA

Start by tracing RetroArch's GL-driver fullscreen resolution and refresh-rate handling on Windows, using the documented 4K AMD reproduction as the baseline and comparing it with the working d3d11 behavior. Done means selecting any listed 4K refresh rate applies that rate on AMD hardware while 1080p behavior remains working.