Will star 69 recognize one ring hang up caller?

Star 69 is a service that allows you to automatically dial the last number that called you. However, it typically only works for calls that were completed. If a caller hung up after just one ring, it's possible that their number may not be captured by the service, depending on the phone system and whether the call was registered in the first place. Always check with your phone service provider for specifics on how their call return service operates.