Stop in for a cup of coffee

How tight was plug when it came out?
You replacing seal while its out?
I would.
The other possible leaks are pump housing bolts and out the case vent.
Overfilled will cause foaming and it will burp out the vent. It will also foam if the fluid if its low.
I hope the plug solves your issue.

It wasn't very tight. I removed and cleaned. When installing and making it tight, it threaded in all the way flush - so about 2 (ish) more full turns. I can change the seal, it only has about 100 miles on it maybe. The trans was full and leaked. It is a pint down (according to dipstick) and still leaks. Should there be sealant on the pump bolts threads?