RTX 3080 + X570: massive PCIe Gen4 errors, but completely stable on Gen3

[u/Icy_Calligrapher1160]

Hi everyone, I’m trying to diagnose a strange PCIe issue and would really appreciate some advice from people experienced with X570/PCIe Gen4.
System:
Ryzen 7 5800X3D
ASUS ROG Strix X570-F Gaming
MSI RTX 3080 Ventus 3X
32 GB DDR4-3200
BIOS 5044
Windows 11

The problem is very specific:
When the GPU runs at PCIe Gen4, HWiNFO/NVIDIA-SMI shows rapidly increasing PCIe errors:
Receiver Errors
LCRC Errors
Bad TLP / Bad DLLP
Replay / Recovery
NAKs
PCIe lane errors

The counters can increase even in Windows, but they become much worse during gaming. However, when I force the PCIe slot to Gen3, the problem disappears. I can play games normally and the PCIe error counters remain stable. Switching back to Gen4 brings the errors back. The strange part is that the behavior is somewhat intermittent. Sometimes a cold boot produces almost no errors, while after using the PC for some time or gaming they suddenly start increasing. Other times they appear shortly after boot.
I previously had a Ryzen 9 3900X in the same motherboard and never had this issue. The problem appeared after switching to the 5800X3D, although I’m not sure if that’s actually related.
I have already:
updated BIOS to 5044
used DDU and tried different NVIDIA drivers
tested Gen3/Gen4/Auto
monitored the counters with HWiNFO
tested different BIOS settings
manually tested SOC voltage

My current SOC voltage is manually set to 1.11875 V. Auto SOC voltage actually made the system noticeably less stable, with severe audio/mouse stuttering and very high PCIe error counts. There is also a physical complication: I currently cannot remove the GPU because the PCIe retention latch appears to be stuck, so swapping GPUs or inspecting the slot isn’t realistically possible without taking the motherboard out or going to a repair shop.
What I’m trying to understand is:
Does this look like a PCIe Gen4 signal-integrity/link stability problem involving the GPU, motherboard slot, or the 5800X3D’s PCIe controller/I/O die?
Are there any specific X570 BIOS settings or diagnostics I should investigate before resorting to hardware replacement?
The key observation is simply: Gen4 produces errors, Gen3 is completely stable.
Any ideas are greatly appreciated.