Hello Patfromny,
To confirm, are you using the Facebook application at the time the iPhone freezes? If so, the steps listed below can be helpful in reaching a resolution. These steps are specific to resolving many application related issues. You can also find these steps outlined in the following article.
- "Force the app to close."
- "Restart your iPhone."
- "To see if updates are available for the app, open the App Store, tap your profile icon, then scroll down to see if updates are available. If updates aren't available for the app, update the software on your iPhone or iPad."
- "Delete the app. When you do this, you might lose data that was stored in the app. Then redownload the app. Then check to see if the problem with the app is fixed."
If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open - Apple Support
If you continue to have issues after those steps, let us know if you sharing something from the Photos app or a different app to Facebook. The more information we have, the more accurate our troubleshooting steps can be.
Have a great day!