Shifting layers

I have recently purchased the dual extruder for my A350T.
I am having a problem with the layers drifting towards the back with each layer.
What should I be looking for to correct?

It doesn’t do it with the single extruder?

This was a problem with an earlier firmware - are you sure you’re on the most recent version? Also: Boxkite’s question is relevant.

I will check again.