Truck cranks slowly or doesn't crank at all after engine warm up?

I have a 1986 Ford F250 I've had starting and charging problems in the past but this one is new… In the morning it starts right up but After driving the truck for about 30 minutes I try to start it again and it cranks slowly or doesn't crank at all. I have a brand new battery, starter and alternator I know all of those parts work great since it starts perfect in the morning and the battery is getting charged 14V while it is running we replaced the positive and negative cable plus we changed the starter solenoid that is mounted on the side of the fender about 2 months ago but I think the starter solenoid is still being the problem I'm going to test it tomorrow to see if it is working properly or not. Is there anything else that could be causing a problem? And everything else on the engine is stock… Thanks

Could be that the battery is weak. Compression is higher when the engine is hot.

One time my brother got a new battery for his 38 Ford with built Chevy 350 engine and it would start when cold, but barely turn over when hot, so he had to get a stronger battery.