If you don't pass through the app and just enable the hotspot from the settings, does your 3DS see it ?
I did some researches, I may be wrong but it seems that the whole tethering feature doens't work with Cyanogen on your device : http://forum.cyanogenmod.org/topic/60336-wifi-hotspot-tether-not-working/
It's a very old topic but they may haven't fixed it yet
edit : but it's not because you have an IP like 192.xxx.xxx.xxx that it's not working ; on my Nexus 5, the exploit IP is 192.168.43.1 and it works fine, I guess it just changes from one device to another
I did some researches, I may be wrong but it seems that the whole tethering feature doens't work with Cyanogen on your device : http://forum.cyanogenmod.org/topic/60336-wifi-hotspot-tether-not-working/
It's a very old topic but they may haven't fixed it yet
edit : but it's not because you have an IP like 192.xxx.xxx.xxx that it's not working ; on my Nexus 5, the exploit IP is 192.168.43.1 and it works fine, I guess it just changes from one device to another