I have been trying get my x1c and two ams units to operate as they use to. Not sure the cause of such issues but suspect updates. I finally resolved the issues without much help from Bambu. Now when loading a file from Maker, then synchronizing the ams and selecting the spool of choice (A3 or 3 in selection pane), slice and send to the x1c. Assuming all is well the spool chosen by the software (B4 or 8 in selection pane) is wrong thus a waste of filament. Tried again using a different part file and same problem. I checked for the settings and they are correct. However, when trying to change the paint colors on a file it seems to be impossible, or it selects the wrong sections or it jus fails to be accurate at all. It may be that the parts are originally processed in a different printer and maybe the G-code does not change when setting the printer type to x1c thus causing many more problems. I have stalled on buying a new printer and may not do so if this is not resolved quickly.
EDIT: I did find a work-around that is sketchy at best, one file works perfectly a different file does not work at all. Another possible choice is change the spool in the SEND window before sending to printer. These are not the best option. It appears the part files are locked so spool/color changes are not allowed, if so this is just crazy.