Duet Maestro on Anet A8 Frame has bad layer shifting

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

you sure it's not mechanical ?
oics of the problem might be a better help.

never used a duet. But steps of 300 - seems like a lot.
Have you upgraded the stepper motors as well ?
Not sure a standard 1.8 degree motor can run at 300 steps a mm

My Camera isn't the best, as is my cable management. The lower one was a previous try and the upper my most recent one. If you need some more detailed pics I can provide.

The extruder is the special motor zou can get with the Titan extruder, the rest are the standard A8 ones. The Duet Maestro runs TMC2224 drivers.