Is your throttle module mapping all set up?
You may have to do it yourself until Turtle Beach submits a predefined controller profile.
Better to ask Turtle Beach why it doesn’t work… SUPPORT@TURTLEBEACH.COM
This is for 2020 specifically, but may help you set it up.
VelocityOne Flightdeck - Suggested Button Mappings For Microsoft Flight Sim 2020 (MSFS2020) - Throttle Module