1992 4Runner ecm issues

I have a 1992 pickup with the 3.0 and a340h automatic transmission.
recently bought this truck from a neighbor, I knew it had some issues and he couldn’t figure it out
after I got it my research lead me to replacing the ecm, which I have done. I got the unit from a company called flagship one, no idea on their reputation, mixed reviews
Now to the current issue, after replacing the ecm it started and ran great. Took it for a test drive, about 15 miles, never once had any issues
got home parked it, left it 6-8 hours, hop in it and put it in gear, rolled about 15 feet and it stopped moving. Put it back in park, shut it off then restarted and the same thing.
finally decided maybe it was the new ecm, unplugged it and plugged it back in then started it and it went into gear. Got it parked and shut it off, restarted it and again nothing. I can feel it going into gear, reverse, drive, 2,1, but I can floor the gas and no movement.
I had a gmc with a problem transmission, I know what a good transmission feels like vs a not good one.
this one felt fine while test driving, but now it’s like it doesn’t exist.
some of my research says ecm/tcm, shift solenoid(s)
Any ideas or suggestions?