For some reason since the very first first time I've played ARK years ago... randomly after hitting Enter after a line of text in the Chat window... doesn't matter if it's Global, Local, etc... it will perform the last whistle that I performed however long ago...
Over the years I got used to it, and just either put all of my animals on 'ignore group whistles' or I'd just stop using whistles altogether.
I've explained this problem to many different people and they all say it's impossible, it's not a thing... but it happens to me, every single damn time. I have had different keyboards, I have had different installations of Windows 10 from scratch, different installations of ARK, but time and time again, no matter what computer or keyboard or installation of ARK I play on, it will eventually inevitably perform a disaster of a whistle after a line of text in chat... soon as I hit 'ENTER'.
It happened again today, and I killed one of my mates. (No big deal, but gees... has anyone else in the entire world encountered this strange behaviour or is it just me?)