Symptom
When trying to transfer a call to a colleague, the call ends up coming back to the initial user's phone.
Cause
When an agent does not answer a call that has been transferred to them, Aircall will return the call to the original receiver. To avoid this, Aircall does not allow transfers to unavailable users (Why is an agent not showing up as an option to transfer to?), however if a call is transferred to a teammate who is available, but they do not answer, the call will be returned to the transferer.
Solution
If users wish to avoid this behavior, each user accepting transfers will need to have a dedicated Aircall number. By having dedicated Aircall numbers for each user, agents will be able to transfer to the direct numbers as necessary and callers will simply go to the voicemail/unavailable message for that number should the receiving user not answer.