If it is happening when hot only, it sounds like it is a line pressure related issue. Have you ever had the transmission flushed to clean out the transmission cooler?
If there was no evidence of an issue prior, this is what I suggest. Take a look through the attachment below. It explains how to test the cooler flow. It will be a little messy, but it will help determine if the cooler is plugging or if there is a different issue.
Let me know if this helps or if you have other questions.
See pic below.
Saturday, September 25th, 2021 AT 8:54 PM