Duet Maestro on Anet A8 Frame has bad layer shifting

[Mottek]

Hey Guys,
Ever since I upgraded my Anet A8 with a brand new genuine Duet Maestro Board I've got a problem with layer-shifting, mostly in the y axis, in both directions and never at the same heights.
Lately it has become so bad I can't use it at all anymore. I checked the entire Frame and I can't find any mechanical issues. I've tightened the (new) belts as well as I can, given that I run a printed carriage for the V6 Hotend with a Titan Extruder as a bowden setup. I even swapped all endstop sensors for new ones and have wrapped those cables in aluminium foil, in the hope that that will prevent signal interferences.

I'm kinda running out of ideas and am really fed up with that piece of crap.
Attached is the config file from the board, you are probably smarter then I am and can figure out if there are any problems.
Please help