A hot engine needs more amps to crank it because clearances such as pistons and bearings tighten up. The connection could barely carry enough current to crank when cold. the starter couldn't spin the warmed-up engine fast enough to kick it off.
Jerry

"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!