Error using google, may be router based

Often when trying to use google on my wifi network, I get access denied or certificate invalid errors on multiple devices


Since it happens on iPhones, iPads, windows PC's, even using multiple browsers, it has to be something with my router

Anyone know what I may have to look for to get rid of this?

Example:





Seems like it's getting hijacked or something like that, but some times it works fine and others it doesn't.