AT temp high message after sitting.

2017 SR5- 101xxx miles- stock battery it has a tune also.

Short intro, past few months been having a Tranny fluid smell when heat is used. Checked for leaks could not find any. The temp gauge is in normal range too. Just this evening wife and I were out and about stopped for twenty minutes to get a snack and drink at Sheetz. When we got back in and started it- it fired up but ran super rough then shut down as if it was running out of gas. Then the message (A/T fluid or Engine oil fluid over temp). Again I checked for leaks and found nothing. Started up after five minutes wait and drove home with no other issues other than the smell of tranny fluid with the heat on. I checked the overflow to see if it had any contamination and looks perfect.

My question, besides the obvious external leak and drawing smell in from outside, what else would cause the tranny fluid smell when heater is on?

I did have tranny serviced about a year ago the lines leaked due to corrosion and were replaced, tranny fluid topped of this was at the dealer.

Thanks!