Starter Overheating?

[Nitrousbird]

'18 SLT Premium Plus w/ the L86, 36k miles.

I first had this problem in mid-June.  Towing my 24' enclosed trailer packed with our SXS and a bunch of other stuff (probably around 7500lbs total), after driving for hours on the highway, pulled off, stuck in traffic for 10 minutes, and then stopped for gas.  Filled up and upon restart, it cranked REALLY SLOW.  Thought it might not crank over but it did.  Temp was in the 90's.

Since then, I've had it happen a couple more times, only after towing.  The last time was yesterday...this time, only towed a 1/2 hour with the trailer empty and hauling nothing else (so 4000lbs).  Only low 70's out and the truck sat for 20 minutes before restarting it and got a slow crank again.

No signs of battery issues.  I will go weeks without using the truck and fires up quickly every time.  Is starter heat soak a normal issue for these trucks?  Should I swap out the starter?  I've owned it since new and this is the first I've had with this problem.   Water/tranny temps all good. 

[Snowcamo]

You nailed it on the head.  Heat soak is what I feel kills these starters. Sounds just like the way mine failed.