I just purchased a 2007 lexus LS460 because I had to sell my 2008 LS460. After lexus informed me that the shift sylinoids were not working properly and an internal transmission oil pump leak. I purchased the 2008 in April and took it to Toyota who claimed it was in good shape and nothing was wrong with it. They did suggest we open the lifetime sealed transmission and change the fluid. I did what they suggested and it was a nightmare ever since. It slipped in high gears and low gears. When is the appropriate time to have your transmission fluid changed from lexus to prevent damage from old fluid? I don't want to make the same mistake again.

 

Some light reading
https://www.clublexus.com/forums/gs-...f-is-real.html

Good chance the shop that serviced your transmission did it wrong meaning the fluid level is not correct.