Well I have just got a GL.iNet GL-MT6000 (AX6000) Flint 2 to replace my TP-Link Archer AX50 (AX3000). Purely because I saw 1 other post on reddit that said it worked lol... And although I was kinda shocked to see a lack of connection settings for my internet connection.. It did work. And actually slightly better speeds (~940mbps instead of ~915mbps).
But the main point is the audio skips and lag spikes (blurry --> unblurry) have almost completely stopped. I do still see some purple lines on the steamlink graph, but they don't seem to effect the game that much.
So mainly updating this in case someone else googles with the same issue. I actually liked the tp-link router, but I doubt I'll be buying another.. The ui on this gl.inet one is a bit basic, but it does the job..
Sorry, I am late to seeing your posts. Not sure how I missed them. But as you found out, the TP Link AX routers aren't great for use with VR headsets. It was problem that they never managed to fix despite numerous firmware updates.
However, I wouldn't let that put you off buying other TP-Link products. Their 6E routers are some of the best out there for VR.