I have recently upgraded my Ryzen 5 1600, Geforce 1050 TI and 400W 80+ PSU to Ryzen 5 3600X, Radeon RX 590 and 650W 80+ PSU.
Since then I have low or fluctuating FPS issues in modern video games such as Borderlands 3 (FPS spikes), Division 2 (unstable FPS) and Ghost Recon Breakpoint (low FPS). I know my system is capable of running these games without any problems. I have seen people play those games with similar systems and without any problems.
Here is my other parts:
MSI X370 Gaming Pro Carbon MB
1 TB M.2 NVMe SSD
Corsair Vengeance RGB 16 GB (8x2) DDR4 3000 Mhz
SonicView 22,5' FreeSync 75 Hz 1ms LED Monitor (DisplayPort)
GPU Drivers 20.5.1
Any help and / or suggestions would be greatly appreciated.