Motorola Moto G — Moto G Problem with wifi connection

I have Moto-G. I have 4 internet connections that I can use on this.
1. Broadband connection #1 through wifi router.
2. Broadband connection #2 through wifi modem.
3. Sim1 internet.
4. Sim2 internet.

I mostly use #1 connection on it.

The problem is: Whenever connection #1 is down, phone will not connect to other connections, neither #2, nor #3 or #4. If I switch off router for connection #1, then after very long time, it will connect to #2. What should be the problem? Will it be DHCP? or any other? Please provide solution if any one knows about this.

Thank you.