Surprising, but it is what it is.
I rarely chalk this up to sandbagging, but moreso that differenent areas are going to have different levels of strength. For example, I had a teammate who struggled as an SL-4 in APA 8-ball. We had a pretty strong region, relatively speaking, so he lost a lot as an SL-4. He moved to a college town that didn't have many strong players. In fact, he was one of the strongest. His winning percentage went up, his total innings went down (due to not losing games that he would have had he been in my area), and he ended up being a high winning percentage SL-6.
So, that's the reality of two different regions that are only 50 miles apart.
Fred