Transmission problem (?) after a transmission fluid change

Crux

Thread necro, I know. I've been searching for a while and this is the closest thread I could find related to the problem I'm having:

My 7AT is basically bogging between up shifts, and I’m not sure what the cause could be.

This is what happens for every up shift: I’m stopped, begin accelerating, the transmission shifts to second, but as it shifts the drivetrain loses power, surges in power, loses power, surges in power again (causing the car to buck a few times), I hear a very faint backfire (occasionally; 1 out of 5 shifts), then accelerates like nothing ever happened.

The car idles and downshifts like normal. It’s a 2009 with 50k, No CEL present, full tank of gas, washed the car last night (maybe water somehow got in the tank?), just had an alignment done ~200 miles ago (ESM issue?), has been UpRev tuned for ~5k miles, oil temps at 180, coolant temps were normal, didn’t lose any electronics during drivetrain power loss, I have not had the 7AT fluid changed like the OP did.

When I accelerate with my foot barely on the throttle, it doesn’t bog. But as soon as I go to accelerate any harder it’ll lose power then surge.

The OP hasn't posted an update and hasn't been active since 2011, but has anyone had/heard of this issue with the 7AT and/or think they know what it might be?

Also, should I take it to a dealership or a local shop?

Thank you in advance for any info!

(EDIT): UPDATE

The Injen air filters currently on the car got water/soap on them from the last time I washed the car. We had a heavy downpour after the car was washed and soap bubbles ran up to the intake manifold causing the car to run like s**t.

Filters were cleaned, battery was replaced (regular 5 year maintenance), and Injen hydro-shields were installed.

Was not an issue with the transmission.

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