If the call fails immediately or cuts out mid-conversation, the first thing to check is your internet connection. FaceTime requires a stable Wi-Fi or cellular signal — at least 1 Mbps for video. Switch between Wi-Fi and mobile data to see which holds better. If you're on Wi-Fi, move closer to the router or restart it. Also check that the person you're calling has an active Apple ID and an internet connection on their end.
Sometimes the mic or camera stops responding during a call. Go to Settings — Privacy — Camera/Microphone and make sure FaceTime has access. If permissions are on but the issue persists, close the app completely and reopen it. A device restart usually fixes hardware-level glitches that software alone won't shake.
Pixelated video or a frozen screen almost always points to a weak connection. Run a speed test — if you're getting under 3 Mbps, the quality will suffer. On cellular, congested networks during peak hours cause the same symptoms. Closing background apps that consume bandwidth (streaming, downloads) can noticeably stabilize the picture.
If the app gets stuck on 'Waiting for Activation,' the issue is usually tied to Apple's servers or your Apple ID state. Sign out, wait a few minutes, and sign back in. Check that your device date and time are set automatically — a wrong timezone can break authentication handshakes entirely.