XB7 dropping connection constantly everyday.

This only started happening recently. We thought it was our older gateway so we upgraded to the XB7. This didn't fix the issue. We've had 2 techs come to look at it but nothing has been solved yet. Sometimes it loses connection for a few seconds and comes right back or it loses connection for up to 20 minutes. It will broadcast the network even though it drops but will say "no internet available". Everytime it drops there is a blinking green light on the gateway but I can't find a manual online that tells me what the lights mean for this model router. Any help would be greatly appreciated.