You can try using a timer that will turn on a flag (a boolean) once the message is printed, and as long as that flag is on, the message isn't printed again. Then after N number of seconds (probably 0.2 or 0.5 depending how quick the spam is printed) just disable the flag again. I had a similar issue with that
here.
(Only issue I see with that is when two people join with the same tag almost simultaneously - maybe someone else can come up with a better fix.)