My org has over 300 Dell 5430 laptops in service. We're having an issue with Miracast connectivity. The connection is unstable, pixelated, and occasionally fails to connect. The issue is resolved by changing in device manager the AX211's 802.11 n/ac/ax Wireless Mode to 802.11ac, instead of the default 802.11ax.
This has been a problem since we rolled these out. I've reproduced the problem with clean installs of W10/11, BIOS versions, driver versions. I've verified that it occurs at home on my LG TV, it's not our use environment. Miracast works flawlessly with our Epson BrightLink projectors, as well as with MS wireless display adapters.
The problem is only with the TVs we use in classrooms. The classroom TVs are not connected to our wired or wireless network. My home LG is networked. We have thousands of Dell laptops in service. It's only with model 5430 AX211's that we experience this.
AX211 Driver version 184.108.40.206
5430 BIOS 1.83
Windows 10 21H2 19044.2364
LG 75UM7570PUD (updated to Latest firmware in an attempt to resolve)
Samsung QN75Q60AAF (updated to Latest firmware in an attempt to resolve)