808f150

So last Friday my truck, 2006 w/5.4 L 83,xxx miles rebuilt stock trans, started slipping. Drove it to the shop had the fluids topped off and was told to drive it and see what happens. Well what happened was after leaving Costco and trying to pull back onto the highway all forward movement stopped, luckily I had reverse and was able to back her down into a parking lot. Got her back to the shop, in 4lo, and it had output shaft speed sensor fault codes read. Shop swapped out the sensor but said the truck still wouldn't move forward, I had another rebuilt trans that I dropped off at the shop. My questions are...
1) has anyone else have trans issues like this, this is the third trans in this in 3 years, I don't drive her hard at all (I'm old now)

2) has anyone had a trans just give up in a day I mean it went from slipping in first a little to not moving at all with no symptoms before

3) could it be an electrical issue with the speed sensor wiring?

Sorry for the long post