Duel Extruder Weirdness

[Slartibartfast 0]

I have just received an A10M by Geetech and am having no end of trouble with it getting it to behave.

 

At present I am attempting to print a 2-tone Benchy:

 

I have the purple filament loaded into "Extruder 1" (E0) and white in "Extruder 2" (E1).

 

It has taken a lot for me to work out what is going on but it seems it completes one layer, finishing off with say white. It then immediately begins the white part of the next layer (which is sensible enough) and when done with all the white bits on this layer the white extruder retracts and the nozzle heads off to the purge tower, which is all well and good. However, upon reaching the purge tower, it lines up about 20mm to the right and shoots out a spurt of filament (that is activated by the purple extruder). After this "squirt" the nozzle then progresses over to the purge tower proper and precedes to print on it but does this using the WHITE extruder. This filament mainly comes out purple though as the "squert" was just done using the purple extruder. Once sufficiently "wiped" the nozzle then travels back to the model and progresses to print the "purple" parts of the layer but it still does this using the white extruder. Once the layer completes the next layer begins with the purple parts being printed by the WHITE extruder. Once all the purple parts are completed the WHITE extruder retracts, heads over to the purge tower, re-engages the WHITE filament again (this time with out a squirt as it was previously extracted), wipes it's nose on the block then precedes to print the white parts of the rest of this layer and the beginning of the next.

 

The weird parts are that...

Firstly the purple parts are printed using the WHITE extruder.

And secondly that the purple extruder gets engaged over by the purge tower on every layer (causing the squert) but is never retracted nor actually printed with. Any idea what is going on?