Just to be thorough, I also went back to 3.4.1 and WIFI server 1.26. Still have an issue with the upload speed. Must be something on the ISP/router side that is creating an issues. You might see some more issues if this is the case.
Looks like upgrading to WIFI server 21.beta 3 fixes it though.
@velvia Unfortunately I went a different direction and abandoned the sensor less homing.
Finally figured it out, had an issue with it loading an old height map.
Found the issue by using the M114 command:
M114
X:255.000 Y:240.000 Z:10.710 E:0.000 E0:47.7 Count 79200 2400 4200 Machine 255.000 240.000 10.710 Bed comp -0.210
The Bed comp was set to 2.5mm, reran the bed mesh and it seems to have fixed the issue.