When the car was new, a few months after delivery in Spring 2000, it developed very harsh shifting behavior that required a software update. The Volvo dealer had some difficulty because the VIN for the 2000 V70 SE (Diplomat Sales) wasn't recognized at first by Volvo U.S.A. computers. It was finally resolved, the software successfully updated and car shifted normally again. That was 15 years ago.

A few weeks ago, I had the battery disconnected while doing electrical work in the engine compartment and cleaning/tightening all of the ground connections I could find.

Coincidental perhaps... I may have lost the stored adaptive shifting profile by disconnecting the battery for a couple of hours? The transmission did seem to shift a bit differently for a few days after the batt was connected again. It's back to normal now.