Nexus 9 WiFi Issues? topic

I cannot use my Nexus 6 or Nexus 9 on WiFi, B/C I don't get my Gmail Emails & Snapchat won't tell me someone sent me something & Also this texting app I use called TextPlus won't tell me I got a Text Message until I turn off WiFi? I can use the Web listen to songs via Google Music All Access. The Videos on YT or Music on Google Music take a few seconds to load, Anybody else having this problem? I have other devices on WiFi like the usual Smartphones and Laptops with One Motorola XOOM Tablet that has never had this problem. I have Comcast Extreme 105 using an Docsis 3.0 Modem with the T-Mobile CellSpot ASUS Router.

Edit: Anyway I can fix this? It would be nice to use this tablet on WiFi most of the time since I get 5GB a month I would really not wanna used that up in a week because I don't get my emails on WiFi.