DFS channels cause slow wireless data transfer speeds on RAX120 AX12

I have been fighting an issue for weeks and finally figured out the cause.  I have A NAS hard drive attached to me router with an ethernet cable.  I also have an IntelAX200NGW wireless card in my Dell laptop.  Everything should be capable of WiFi 6 speeds.  I have been noticing varying transfer speeds through my wireless connection.  Occasionally I would get great file transfer speeds to the NAS.  60-80MB/s when things were working correctly so I knew it was possible.  About 90% of the time I would get 40-50MB upload speeds from my laptop to the NAS and only 3-4MB download speeds from the NAS.  When I looked into the WiFi status on my laptop, I would see connection speeds near 2gbps but sometimes it would drop back to 54mbps so I knew something was wrong.

I tried everything possible with software, drivers, windows reset, router reset, etc.  I finally stumbled onto a fix.  I changed my router's 5G WiFi to a non-DFS channel.  The problem is gone.  It doesn't seem to matter if the AX option is checked or not.  As soon as I select a DFS capable channel, I start having slow data speeds.  Has anyone else seem this or found a fix?  I would like to get the extra speed from the AX feature.  I am not getting file transfer speeds of nearly 100MB/s download from the NAS and 60-70MB/s upload to the NAS.

I had the same issue with a Killer wireless card as well.