Failing 7AT , Torque Coverter or Other?

Tractionless

90k miles on 2010 with only CAI and axleback exhaust.

Trans. Fluid fully changed at 72k and didn't exhibit any signs of burning etc. Dumped again at 82k and it still looked, smelled new. Has a cooler since 80k miles.

When attempting some tuning pulls in manual mode 3rd gear at 2k rpm it twice instantly surged to 3k before settling back down to 2k and taking off. Almost like it I was put in neutral and back in gear. This happened twice within 10 minutes of doing 4 pulls, two pulls it didn't happen.

Other than that the transmission has behaved normally, no codes, no AT light.
Does this sound like symptoms of a torque converter issue or other in your experiences?

Thanks for any insight you can lend.

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Toys Not Tots