vegetaleb
I have bizarre dow connections for whatsapp on all my home family mobile phones, Sony,HTC,Apple...
When I send messages sometimes it take up to 2 minutes to send them, and people online status don't appear for 5 minutes, sometimes messages arrive 30mins later!!!
I doubt it's the whatsapp app or phone problem as in my gym club wifi and my ex-job wifi I didn't have this problem at all.
I have a TPlink modem wifi router TD-W8961ND with latest FW flashed and firewall off
TPR0
Happened with me with a cheap router only when downloading torrents, guess it couldn't handle the p2p traffic.ping from wifi to ethernet device connected on the router, just to test load.