So I just purchased a RB750 for my home. My cable ISP is simply a DHCP connection type. I have it all setup but the WAN connection simply doesn't pull the DHCP from my ISP..... Under DHCP clients tab is just stays as "searching".

The weird thing is I had setup a CCR1009-8G-1S-1S+ at home with the EXACT same settings and it worked perfect. So I am at a loss.... It is not a NAT issue or anything because it is not even pulling the ISP address to be a NAT issue even if it was the issue.....

Have you configured the DHCP-client on the correct interface?
Try another cable?

Maybe you only get one wan ip from your isp.
If soo, you need to release the the old wan isp ip from your old router, before you get a new wan ip to your new router.
Connect your old router first and then press release.

So I just purchased a RB750 for my home. My cable ISP is simply a DHCP connection type.

In addition to whatpatrikgsaid, many cable ISPs limit the number of MAC addresses that their modems will bridge, and often the modem will hang on to a bridge table entry after it learns a MAC for a long, looooong time. If you change the router or whatever device you have plugged into the cable modem, you may have to reboot the cable modem before you can use the new device.

-- Nathan

去to IP-address and delete the IP-adress on the DHCP-client
去further to IP DHCP-client delete the DHCP-client and make a new one
You got now a new IP-adress from your provider if not restart the isp modem
and try again.