WiFi issues

[AC Question]

Greeting everyone.
Recently, I got new internet / modem and now I can't connect my LG-G5 to WiFi.
Here's what happens.
No matter what WiFi I chose from my modem (had two versions 2.4g and 5g) and when i connect to one or the other, the lg-g5 is stuck in a continuous loop of connection, disconnection, connection, disconnection. It disconnects 1 second after it connects. Sometimes it even provides this message "Internet unavailable with 0x" or something along those lines. Any help??? I've wasted all my data because of this.
Thank you

EDIT: Also shows message "<unknown ssid>" or something like that at times

 

[B. Diddy]

Welcome to Android Central! Review this guide and see if anything helps: http://forums.androidcentral.com/am...roubleshooting-wi-fi-connection-problems.html