Problem solved. Added an outdoor AP driven by a powerline kit. Fixes 5ghz connection issues and also takes the load off the 2.4ghz on the c3150. Everything connects and works well now.

I disabled my dhcp reservation table and switched to an alternative: (by programming the required ip directly into 21 of the IoT devices, outside of the dhcp pool and started using ARP reservation...

I have been having major issues with this router, basically since I bought it. For some reason (even with smart connect disabled) The router locks devices out of connecting to the 2.4 ghz network...