I have the following personal security dlink cameras.  They all have the latest firmware from http://support.dlink.com
1.  DCS-5010L with 1.03 (2014-01-22) firmware
2.  DCS-5222LB1 with 2.01.05 firmware
3.  DCS-5020L with 1.03 (2014-01-22) firmware
4.  DCS-932L with 1.09 (2014-03-14) firmware
I have an Apple Airport Extreme wifi router with latest firmware 7.7.3  All 4 of the cameras connect to the wifi fine using “WPA2 Personal” security.
Camera 1:  Connects fine
Camera 2:  Connects fine
Camera 3:  Connects fine
Camera 4:  Connects fine
I also have a Linksys EA6500 (http://support.linksys.com/en-us/support/routers/EA6500), with firmware Ver.1.1.40 (build 160989).  All the cameras connects fine as well.  Both the 2 GHz and 5 GHz channels have the same SSID.  I used WPA2/WPA Mixed Personal security on both channels.
Camera 1:  Connects fine
Camera 2:  Connects fine
Camera 3:  Connects fine
Camera 4:  Connects fine
Now I have a new Linksys WRT1900AC (http://support.linksys.com/en-us/support/routers/WRT1900AC), with firmware Ver.1.1.8.161917, which I want to use going forward.  Three of the cameras won’t connect to this router.  Both the 2 GHz and 5 GHz are the same SSID.  Im using WPA2/WPA Mixed Personal security on both channels, and the same Wireless SSID and password as with the Airport and EA6500.
Camera 1:  Won’t connect
Camera 2:  Connects fine
Camera 3:  Won’t connect
Camera 4:  Won’t connect
I need help one why the 3 cameras wont connect.  Any ideas why the Linksys WRT1900AC wont allow the wifi connections?  Is it a Linksys router or a camera issue?
Any suggestions would be appreciated.
Thank you.