1. His district lines have been redrawn.
2. There is a LOT of strong anti-incumbent sentiment among voters on BOTH sides of the aisle.

The top is how the district was as of the 2022 election, when Andy Ogles first got elected (and notably, this was after the district had already gotten redrawn to split away from Nashville, which helped contribute to the seat being taken away from Democrats for the first time since 1875).
The bottom is what it looks like now, as of this year's primary election.
Geographically, they're 80-90% different constituencies entirely.