+1 found iPad ringing 4 hours after call on iPhone had finished. The iPad even had its cover on thus on sleep mode. Battery drained.
I use telegram on two phones, android and iphone and I normally go around with only one of the two. By definition I answer a call only on one and if that is the android phone then it means that the iPhone will ring until the battery is fullly depleted and I usually find that when I came back home. That is making Telegram unusable. The phone should stop ringing when either the call has been answered on another device or a certain amount of time (e.g. 30 or 60 sec as suggested) has passed.
1.5 years, this still not fixed. I've tired charging my ipad everytime after somebody calls me via telegram. Call should be declined on other devices as soon as i answer on any of them