Weird, yeah, it’s injecting a second, direct course to KJWN that is bypassing the filed route. You can see that even though that leg is not active, it’s predicted (by means of connection and curve) from your present position, almost like you’ve got two routes to the destination rather than one out and one back.
I have never seen this because I refuse to use the World Map to generate my flight plan. However, I just tried using it with a different airport pairing, complete with IFR routing and approaches, and sure enough, it injected a second, direct line to the destination. Deleting and re-entering the destination in the Garmin caused the second line to go away and it looks normal.
However, skipping the routing section of World Map and entering it all manually does not replicate the issue - it behaves normally. Additionally, using the IFR routing in the World Map, but not selecting an approach (leaving the approach “automatic”) causes it to behave normally.
So it’s just when you select an approach in the World Map.
Looks like you found a legit bug!
That said, I’d never plan on a specific approach until I’m close to or on descent and I get the “expect” from ATC or ATIS.