Starter "Heat Soak" - common or possible failing (new) solenoid??

[Fixit]

Just got done with a 180-mile run at varying highway speeds with #9365. Did a lunch stop after a 80 miles stretch (about an hour), a fuel stop at the 100 mile mark (about 10 minutes) - not an issue/problem with a restart after either.

After the final 80 miles I pulled up to the house, shut it down, shlepped in some stuff, and went to move the car (approximate time 20 minutes). No Start.
(The fuel pump pulsed, gauges swept, even heard the Coyote underhood start request relay trip...everything as it should be except no cranking.)

I let it cool down to where the sidepipes were warm/touchable, and slid underneath as best as my beer storage reservoir would allow.
My 1st thought was "Did I leave enough slack on the solenoid trigger?? Maybe the engine torqued and pulled the wire out of the terminal?" Nope, still connected... however
I nearly burnt my hand/fingers on the solenoid & starter... They were HOT!

I let it cool down another 15 minutes, twisted the key, and Vroom. Popped right off as it always has.

What's your thoughts guys??

There's nothing in tight proximity to the starter except the engine block... or at least in comparison to a Small Block Chev with headers (I know all about heat soak on those!) How's this thing getting so hot?