I am still new to 3D printing, but have had good success on my prints until now (PLA and PETG). So I purchased the MMU3 upgrade, and now I am trying to print the printable parts.
"MMU Unit1_0.4n_0.2mm_PETG_MK4S_5h27m.bgcode" printed just fine, as far as I can tell.

However now I can't get a good print of "MMU Unit2_0.4n_0.2mm_PETG_MK4S_6h21m.bgcode". I don't know how to troubleshoot from the symptoms I am seeing, can someone please help me out?

My setup:

• MK4S
• HF0.4 nozzle
• Textured sheet
• Jet Black Prusament PETG that came with the conversion kit
• Source files https://www.printables.com/model/531604-mmu3-printable-parts

1st print was all messed up, noticed after checking on it because I heard clicking/obstruction sounds.
(no pic)

2nd print I cleaned up everything including the filament material from around the nozzle and tried again, but this time watching it I could see the first layer didn't get printed correctly.

3rd print I saw recommendations to re-slice for myself, since the Prusa-provided bgcode files show SPEED instead of QUALITY.
So I re-sliced as follows per the printables page & files:

• Print settings: 0.2mm STRUCTURAL (note that QUALITY is not available due to Input Shaper feature of MK4S)
• Filament: Prusament PETG
• Printer: Original Prusa MK4S HF0.4 nozzle
• Supports: None
• Infill: 20%

But it was still a failure.

4th print I dried the (still new) filament at 145 deg F for 5.5 hrs, but it was still a failure

What am I doing wrong?
Or rather, what do I need to do in order to have success?

Thank you!