Hello,
I need to block Whatsapp traffic on the router. I found some old guides on the web, but they are quite old. It seems they don't release anymore their server's IP. I tried to firewall some ports but without sucess. Do you have an idea? Thanks

Not sure, but you can try to block ports
Try to block url name in http
Try to block url name in https ( search for tls mikrotik)
Try and create blacklist??

https://www.solvemix.com/index.php/andr ... w-it-works
https://github.com/ukanth/afwall/wiki/H ... g-WhatsApp