Hello ATLBIGDAVE,
If you've already started this process, some of this reply may not apply. However, we'd suggest backing things up prior to restoring the device to factory settings: Back up iPhone - Apple Support (That way you can always restore from that backup, if needed: Restore your iPhone, iPad, or iPod touch from a backup - Apple Support)
With that said, after restoring to factory settings: Restore your iPhone, iPad, or iPod to factory settings - Apple Support Were you able to test out SharePlay and Screen Sharing? If so, did you have success with sharing your screen after restoring or no?
Keep in mind, that the other person would also need to meet the requirements for SharePlay and Screen Sharing: Share your screen in a FaceTime call on iPhone - Apple Support
Share your screen in a FaceTime call on iPhone
In the FaceTime app
, you can use SharePlay (iOS 15.1 or later) to share your screen in a FaceTime call—you can bring apps, webpages, and more into the conversation. You can show off a photo album, plan your next vacation together, or get feedback on something you’re working on, all while seeing and hearing the reactions of others on the call.

1. In your FaceTime call, tap the screen to show the controls (if they aren’t visible), tap
, then tap Share My Screen.
A countdown from 3 to 1 appears on
, then your screen appears in the FaceTime conversation for everyone to see.
2. Go to the Home Screen, then open an app you want to share in the call.
Let us know how it went, take care.