Just checking on things, no offense intended for anything I asked and I apologize if it came off that way.

The voids we’re seeing look like possible under extrusion and I didn’t see that mentioned before. If you haven’t changed any of those settings that is likely not the issue. All of the printers I’ve worked with do just fine with default settings.

Do you have infill set at 100%? I may have missed that detail. What pattern is selected for the infill? Some patterns work better than others.

How tight are the rollers for all three axes? They should be just tight enough to prevent any wobble in each direction. Too tight and the print head might be restricted.

Last thing for this round: Since you’re getting smudges of the other color, your temps may be set too high.

Just some late night thoughts for now. Hopefully something might ring a bell.

What size nozzle are you using? Also have you messed with extrusion settings at all, especially amount? I feel like the previous advice had you change an advanced setting when you’re dealing with a basic setup issue.