I've been getting great prints when printing using the right print head on my Monoprice 3DP (rebranded Flashforge Creator Dual). When I try to print with both print heads though, I can't get it to work. I've selected the Creator Dual profile, set the temperatures on both heads, set the support structure to be the first print head (which is loaded with PVA)...etc. But when I export the file to print, load it on the printer, it only ever warms up the right head and prints those items, no action on the left print head with support.
In the Print Preview window I see it generating the support code, and when I look in the .gcode (although the printer uses the .x3g code to print from SD card) I *seem* to see the settings in there properly for both print heads.
Any suggestions/clues as to how to debug this issue? Thanks.