Ballast resistor Q's

I used the search function and read about 50 threads and did not find any with my exact problem.

I have replaced the coil, rewired the ignition, replaced ICM, New plugs, New wires, just upgraded to an electronic dizzy all within the last 150mi

I replaced the 4 prong Balance resistor about 900 miles ago.

When the car is cold it fires first turn, stays running and runs like a champ as long as I don't shut it off. It is fine if I drive all day long if I don't shut it off. BUT, once it is up to running temp, or driving for 5-10 minutes and I shut it down....

It still fires immediately on the starter. But as soon as I let off the key it falls on its face and dies the second I let go of the key. If I let the car sit for 20 minutes or so it will fire up properly again.

Is this a sign of a bad/dying BR or something different?