That AX200 bootup problem occurs on dual-boot Windows/Linux systems. The solution is to turn off Windows "Fast Startup" so that Windows does not leave the AX200 in a "locked" state between reboots.

https://community.intel.com/t5/Wireless/Unstable-AX200-conne...

Also, the latest Intel iwlwifi firmare is slowly evolving to address crummy AX200 speed issues that Windows does not suffer. On one of my laptops the AX200 is all over the place speedwise, but running wavemon shows it stabilize in the 600 range of rx and tx after awhile. Here's hoping for progress with that firmware on Linux.

https://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/linu...