Framerate low in editor modes but high in packaged project

I’m struggling to troubleshoot my FPS issues with UE 4.18.3. Here are my numbers:

FPS & Frame Time:
60 and 16 (VR packaged),
27 and 36 (Simulate),
15 and 67 (VR Preview),
40 and 23 (Standlone).

I’m using the VR recommended settings (XR Best Practices in Unreal Engine | Unreal Engine 5.2 Documentation).