Hi @jsh,
Yes, this is likely a Nav2 tuning issue combined with the fact that the robot cannot move backward.
First, make sure your Nav2 controller/planner is not generating reverse motion. Depending on the controller, there are usually settings to disable backward motion or use forward-only behavior.
The spinning near the goal is also commonly caused by strict final orientation matching. I would try increasing xy_goal_tolerance and yaw_goal_tolerance.
Best,
Jason