T-Mobile home wifi interference with T-mobile phone

I have noticed that when I am home and try to open web sites on my phone, I cant if I am connected to my TMobile home wifi. If I disconnect my phone from the wifi I can download the sites. I went into the store and they had no idea why this is, telling me I need to disconnect my home wifi base and bring it in so they can see it. I dont want to mess with our working home system by disconnecting. Does anyone have insight into this issue? The rest of my family has no issues - but they use Apple phones while I have a droid. And, yes, my droid is up to date on software.