SSID sending odd addresses

> How do I correct this issue with the wrong addresses being handed out?

   First, determine who's handing them out?

   It's extremely unlikely that the DHCP server in your C3700 is
dispensing IP addresses on multiple subnets.  Much more likely, there's
some other gizmo in your neighborhood (on your LAN?) which is running
another DHCP server on that other subnet.  That might be some
Internet-of-Junk device which creates its own hotspot, with the intent
of letting you (using a web browser or some special app) communicate
with it, to allow you to configure it (so that it will use _your_
wireless router, and disable its own).

   It's conceivable that some such IoJ gizmo has gone rogue -- lost its
original configuration, or never had one, or just went nuts -- and is
desperately crying out for help.

   In such a case, you might try disabling the radios in the C3700, or
changing the SSID(s) on the C3700 and see if you still see the old
SSID(s) (from the rogue gizmo).  You could also have some wired device
which is running its own DHCP server.  As usual, many things are
possible.  But the C3700 causing this on its own is among the least
likely.