When my Tranny died a couple years ago my symptoms were similar. I would be going into a turn at about 15, then go to accelerate and BAM it would slam into gear. Finally my Transmission died in traffic when there was a slow down and then a speed up. Did a normal/hard accelerate and BAM. Only had 2nd gear. Took it to the shop and I had to have my entire tranny replaced. I would get it serviced asap.

The torque converter has me interested though. Mine will do similar actions as the video shows while cruising at 30ish under load (usually up hill)

I do not have Superchips though