4L60E stays in 4th when warm

[MO LS Noobie]

I have a 99 Tahoe 5.7 Vortec with a 4L60E that I transplanted a 6.0 LS LQ9. I have the tune fairly squared away except when fully warmed up, driving down the highway in overdrive, torque converter locked up. When I slow to a stop the transmission stays in 4th. Torque converter clutch unlocks properly but it has no torque until I manually shift into third, or any lower gear it immediately shifts to first and accelerates properly. The transmission then works properly till I'm on hiway for 10 minutes or more. Always works properly around town.

I have installed the PCM in another vehicle and it does the same thing. I'm running a 462 PCM to allow air-conditioning operation and 603 operating system, the BIN file is attached below

Any help/suggestions appreciated.

[MO LS Noobie]

Never found the issue, went back to original tune and started over. All is well.