I selected ABS for extruder 1 and ninjaflex for extruder 2. Then for extruder 1 I choose custom, dual extrusion, enable prime tower and see the Prime Tower Y position is 267.5289. Then I do the same for extruder 2 and see the Prime Tower Y position is 268.4 with more digits I don’t recall.
Today the program does not do it any longer, so I guess it is just one of the many bugs still there.