The only way I’ve found to get round this and I was on the phone with apple uk for a hour today who were very helpful but couldn’t solve the problem.Ok upload your video to iCloud then you can share it with Facebook,absolutely ridiculous I know but since my iPad Pro was updated in November 2020 this is the only way me personally can share videos to Facebook,YouTube or photos not a problem.Happy new year all and stay safe,Dave.
Hey there Davesflint193,
Thanks for reaching out to Apple Support Communities. We understand that you're having some issues sharing videos to Facebook. We're happy to provide point you in the right direction.
First, make sure the app is updated:
Update apps or use automatic downloads
If the app is updated, contact Facebook for further assistance:
How to contact an app developer
We hope this helps.
Have a great day!