Hi Cindy
I have no problems with having to sign in as like you I don't log out and I use my home laptop and my works pc and they both keep me logged in, so does my kindle fire when I can't be bothered to switch on the laptop and wait for the wifi to kick in ( this tiny kindles much quicker believe it or not )
it may not recognise the user if your using too many devices or your ipads relatively new until it gets used to you using it more regulary, I find this with my bt email as from time to time I will be asked for my log in details
hope this settles down soon
Dave