Does not always start once it has warmed up

This sounds like a crank sensor is beginning to fail. What happens when these sensors is when they get hot they can actually go to an open circuit and this causes the engine to just cut off. It will restart when the sensor cools down. Here is a guide that talks more about this:

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

There are many other causes of this so here is a video that talks more about this.

https://youtu.be/dCjmRL3p4Cs

Basically what we need to do is when this acts up again is check for spark and fuel when it is not starting. The best way to do that is when it will not start, spray a little starter fluid in the intake and see if it starts. If not, then we need to pull a plug and check for spark. This is done by holding the plug against the block and crank the engine and see if there spark.

Lastly, if you decide to go ahead and replace the crank sensor, I would replace the spark plugs as well. There is an issue where we have found that the spark plugs get worn and they give off an RF signal and it interrupts the crank signal and the PCM cuts the engine off. Normally when this is the case the engine starts back up right away but I would replace them just to be safe.

Let me know if you have questions. Thanks