I came here to report the same thing! Guessing iniBuilds “enhanced” the Boomerang by adding the FS2024 custom pilot. I don’t think it’s a bug (other than the size) but rather it’s by (poor) design.
Swapping back to the original not only gives you back the good-looking pilot, but also lets you fly with the canopy open! The FS2020 version seems to work just fine in 2024, at least on a quick test flight.
What I don’t understand is why I had the period pilot the very first time I flew the 2024 version. I tried zeroing out the pilot weight, looking for something in the cockpit to click, etc, to get him back and no dice. So reverting to the 2020 plane in 2024 was the solution.