I tried mesh of 2x ax3600 on global and chinese and it's spamming ntp all the time.
On global i was limited to 93Mb/s on wifi on 2nd router.
Have you found any solution? Maybe openwrt?
You need to find manually all possible permissions manager. You must have slipped some. I had same issue.
check all positions here for antutu and antutu 3d