You record a clip on your iPhone and try to set it as your Telegram video avatar. Telegram says nothing. No error, no format warning. The upload completes and your avatar doesn't change.
I spent an embarrassing amount of time debugging this.
The Silent Rejection
Modern iPhones shoot HEVC (H.265) by default since iOS 11. It's a better codec. Files are smaller. Most apps handle it fine.
Telegram's video avatar uploader does not. It silently rejects any video that isn't H.264. No error dialog, no format hint. You just never see the avatar update.
