Q: Itunes help

I can only sign in to iTunes when I connect my iMac to the internet through the hotspot on my phone. I can not sign in on my iPhone or iMac when connected through my home internet. I keep getting the time-out and i need to check my network connection message. I can access the internet via wifi on both iMac and Iphone6 so i know i have a good connections.

thanks in advance for the help