When the trans is placed into any gear and the vehicle is not moving, no gear train parts are rotating inside the trans case.
That is why I posted the converter is the cause, unless you have an engine problem that causes the engine to stall.
If the converter clutch is applied for some reason, you put the trans into gear, the engine dies.
If the engine has problems, that may cause it to stall out when placed into gear
Some people are like Slinkies... Not really good for anything, but they still bring a smile to your face when you push them down a flight of stairs.