Honda Pilot 03' w/188k miles. Its losing acceleration. What could be the cause?

What is your question?

If I drive the vechile up to 1-2hrs I notice I start to lose acceleration, not being able to go over 20mph, I pull over to the side. A light has now also start to come up that says A/T Temp. I have taken it to Honda and other mechanics and no one seems to find the problem. The transmission fluids have been drained twice. Checked the senors everything comes back that it's in working condition. Some have said just change the transmission and another said it's probably the computer not working properly. Has anyone experienced this before?

What makes this problem better or worse?

Not sure if it’s the times I turn it off/on or driving the vechile for a long time.

How long has your 2003 Honda Pilot had this problem?

A few months.