Low FPS on native Linux, works fine on Proton.

[Szymon KURZACZ.pl]

Hello.
I've tried to play on the native Linux version but it sticks on very low FPS, like 5-10FPS, no matter what settings are chosen or if it is running in windowed mode or not.

Today I tried forcing the game to use the windows version with Proton 7.x and it started perfectly and keeps 30FPS without any problems on max settings.

System:
  Kernel: 5.4.0-146-generic x86_64 bits: 64 compiler: gcc v: 9.4.0 
  Desktop: Cinnamon 4.8.6 Distro: Linux Mint 20.1 Ulyssa 
  base: Ubuntu 20.04 focal 
Machine:
  Type: Desktop Mobo: ASUSTeK model: PRIME B450M-A v: Rev X.0x 
  serial: <filter> UEFI: American Megatrends v: 2006 date: 11/13/2019 
CPU:
  Topology: 6-Core model: AMD Ryzen 5 3600X bits: 64 type: MT MCP arch: Zen 
  L2 cache: 3072 KiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 sse4a ssse3 svm 
  bogomips: 91029 
  Speed: 2388 MHz min/max: 2200/3800 MHz Core speeds (MHz): 1: 2265 2: 3587 
  3: 2053 4: 3596 5: 3568 6: 2101 7: 2133 8: 3445 9: 2078 10: 3419 11: 3559 
  12: 2182 
Graphics:
  Device-1: NVIDIA TU116 [GeForce GTX 1650 SUPER] vendor: Gigabyte 
  driver: nvidia v: 515.105.01 bus ID: 09:00.0 
  Display: x11 server: X.Org 1.20.13 driver: nvidia 
  unloaded: fbdev,modesetting,nouveau,vesa resolution: 1920x1080~60Hz 
  OpenGL: renderer: NVIDIA GeForce GTX 1650 SUPER/PCIe/SSE2 
  v: 4.6.0 NVIDIA 515.105.01 direct render: Yes