Hello Vanejz,
Thanks for using Apple Support Communities. It sounds like you’re having trouble with FaceTime. I’m happy to help. If you haven’t already, I suggest turning FaceTime off by tapping Settings > FaceTime and toggling it off. Once you’ve done so, restart your device, enable FaceTime, and test the issue again.
If the issue persists, I suggest making sure you’re iOS is updated:
Update your iPhone, iPad, or iPod touch - Apple Support
Lastly, I suggest reinstalling the iOS. While this shouldn’t remove any information from your device, it’s good to create a backup before-hand:
How to back up your iPhone, iPad, and iPod touch - Apple Support
You can find instructions for reinstalling the iOS in the article below, under the section labeled “Put your device in recovery mode and set it up again”:
If you can't update or restore your iPhone, iPad, or iPod touch - Apple Support
Let me know if that helps.
Take care.