Latest Firmware Causing Issues
I updated my MK4S last night to the latest firmware and noticed when selecting PLA and waiting for it to heat up...it goes to 232 degrees instead of 230 making the PLA real soft and melting too much. The next thing I noticed was when a print was finished and got to 100%, you'd normally rotate the knob to the right and select home. Mine just hung there and I had to hit the reset button. Finally, I noticed when unloading filament, it now retracts and leave a blob on the nozzle where before it would unload perfectly and drop a section to the bed and then fully unload so you could pull it out.
RE: Latest Firmware Causing Issues
I assume you updated to firmware version 6.4.0? You might want to revert to 6.2.6 as there have been a lot of issues with the later version. I can’t understand why Prusa hasn’t at least acknowledged the problems and promised fixes. They appear to be more focused on selling Core Ones, touting features that won’t be available for months, at best.
MK4S/MMU3