Winning the jamathon!  

Winning the jamathon!

Hello, I need some advice about my Prusa Mk2. It has served me well, But it no longer prints properly.
It's jamming internally. It goes through the motions of printing, but is no longer extruding plastic.
I can un-jam the machine by simply stopping the print, and unloading the filament. I then reload the
filament after cutting a new edge. But my partial prints are trash.
It seems to be heat creep, but i don't know how to stop it.

I have replaced everything from the Bondtech gears down to the nozzle, including the heat block, thermistor, heating
element, sock, and my tube inside is direct replacement from Prusa. My replacement heat brake is made from titanium,
and my fans are all working/correct facing, etc.

My filaments are Prusament
No enclosure. I live in SW Florida, so heat is more of a problem than cool.
Ambient temps are approximately 74F. Go team air conditioner!
It jams at all temps with PID calibration from 215. 209, 203, to 192, with correct g-code arguments from each iterative setting change.
I have adjusted my retraction settings from .8mm to .4mm, and slowed my retraction speed to 25. No better.
Set retraction to 0, And then successfully completed a 17 hour print. I then completed a 20 hour print!
I then attempted a 1.15 hour print, and it jams. Repeatedly.
Please note the machine is not partial under-extruding. It's working properly, or nopes out entirely.
No debris on build plate.
I don't have much confidence in my machine. I cannot predict it's behavior and I'm kinda depressed about it.
Some helpful advice would be appreciated, Thank you.