Iphone Faster Not Connected To Wifi

I have interenet service, wifi, over 100mbps, via my iphone speed test app.

when I use my iphone(not my computer which is hardwired into my interenet via cord)

when I use facebook or google and I'm connected to my wifi, it runs slow or not at all
then I simply turn off the wifi and I use my date plan(sprint network on my iphone 6splus) it works/connects!

this is new, i use my wifi to watch netflix, etc

 

could this be because the phone that is slow when it connects to the wifi, has a SIM card in it that doesnt work?

so the phone has a SIM card init, but is not on any carrier or data plan, I only try to use wifi with it
and when the wifi is slow,I turn OFF the wifi and the phone then load so the page

which makes no sense, cause it is not on a data plan and I cannot make calls with it.

 

good call,I"ll let ya know