When I save my world after playing and IMMEDIATELY  exit the game, Minecraft crashes.    If I wait 1 second or more, no crash occurs.

System:
  Host: <name> Kernel: 5.4.0-48-generic x86_64 bits: 64
  Desktop: Cinnamon 4.4.8 Distro: Linux Mint 19.3 Tricia
Machine:
  Type: Desktop Mobo: ASRock model: X570 Taichi serial: <root required>
  UEFI: American Megatrends v: P3.00 date: 04/07/2020
Memory:
  RAM: total: 15.57 GiB used: 2.35 GiB (15.1%)
CPU:
  Topology: 6-Core model: AMD Ryzen 5 3600X bits: 64 type: MT MCP
  L2 cache: 3072 KiB
  Speed: 2197 MHz min/max: 2200/3800 MHz Core speeds (MHz): 1: 2199 2: 2199
  3: 2195 4: 2192 5: 2200 6: 2200 7: 2201 8: 2202 9: 2200 10: 2199 11: 2199
  12: 2191
Graphics:
  Device-1: NVIDIA driver: nvidia v: 450.51.06
  Display: x11 server: X.Org 1.20.8 driver: nvidia
  unloaded: fbdev,modesetting,nouveau,vesa resolution: 1680x1050~60Hz
  OpenGL: renderer: GeForce GTX 1660 SUPER/PCIe/SSE2
  v: 4.6.0 NVIDIA 450.51.06
Drives:
  Local Storage: total: 6.37 TiB used: 3.07 TiB (48.2%)
  ID-1: /dev/sda vendor: Western Digital model: WD20EADS-00W4B0
  size: 1.82 TiB
  ID-2: /dev/sdb vendor: Crucial model: CT1000MX500SSD1 size: 931.51 GiB
  ID-3: /dev/sdc vendor: Western Digital model: WD40EFRX-68N32N0
  size: 3.64 TiB

Crash report:

hs_err_pid14346.log

Update:

It seems not (much) to depend on the time between saving and exiting, the crash occurs randomly (but frequently).  The saved world is OK though.