Thanks for your advice and replies. Up to now I have followed your advice and done the following. Unpicked the beta test program button. Then clicked restart oculus (box above the beta button). On restart it done a full software update (a revert?)
I started up MSFS and left the oculus debug tool completely on standard settings. CTRL and TAB to activate VR when on world map mode, then started clicked fly. I experienced 2 white flashes on the loading screen to which I thought it hadn’t worked, and then I started at the gate and no more flashes. Thank you for the advice!