Default Network disconnects when connecting to wifi

Hi,

I'm on 4.4.3, stock ROM, no root. Whenever the ph connects to Wi-Fi the network disconnects and takes about to min to connect back. I saw this on 4.4.2 too and the same continues. Is this a known issue? Any ideas how to prevent this?

Thanks.

Sent from my Nexus 5 using Tapatalk