[Solved] 802.11ax worse than 802.11ac with mt76 driver?

Well, I can confirm that in fact OpenWrt performance in 802.11ax with the AX6S seems to be problematic with an iPhone 13 Pro.

I received today a new AX6S, and before flashing OpenWrt I did the same test I did before. The stock firmware has a much better performance than OpenWrt.

Just remembering that this scenario is with one brick wall between the router and an iPhone 13 Pro. In the same room and with the phone in the router's line of sight everything works as expected. Across the brick wall a Windows laptop (with an 802.11ax cart) has a slower but consistent performance both with the stock and OpenWrt firmware.

So at this moment it seems an specific problem with iPhone. Before flashing OpenWrt I will test if an M1 MacBook Air to check the results.