Aisin Transmission shift issues

[Pegasus]

2008 9-5, 92K miles.

Bought 3 weeks ago and now have a situation with the transmission shifting between 2-3000 RPM while accelerating on the highway. When the transmission downshifts @ 60-65 MPH and hits that range results in hesitation like I hit the rev limiter, and if I hold my foot to the floor it will rev past but not for long. Yesterday it happened while moving from a stop. Choosing Sport mode reduced it but it still exists. A reprogramming perhaps?
It did not do this when I test drove it and bought it, but did before and after the installation of a new battery this past Thursday. Need help.

Also, since I could not confirm the type of fuel that was used by the previous owners, it has only been fed Shell V-Power Nitro since the day I have had it. STP Ultra 5 in 1 fuel system cleaner was added to the first two tanks, then Chevron Techron with the next, then Gumout All In One with the next. All are certified to be used with Direct Injection engines. New NGK plugs were installed prior to my taking delivery.

[swisssaabist]

did you flush the fluid ? a bad /old fluid have degraded properties every 40-50K you need to change this, it contains 7lt you can't have at once so the procedure is to flush 4 lt each time run for few days and do it again for three times like that you've 92 % fresh fluid.
generally it resolve issues coming up without codes--> (meaning the valves are defectives )
So start with that and see what's happen.