iPhone 6 safari key board issue

Hi my name is Carlos I'm new here and wanted to say hi and I just got my first iphone.
its an I phone 6. So I'm very new and have been talking to the apple disability help desk a lot these days.
I just discovered something rather unpleasant I'm thinking my phone might be broken and I was going to go to my local apple store tomorrow afternoon.
After talking to a few different apple disability reps and they are not having any clue of what is going on.
The problem is when I open safari and type in a web site.
when I get the user name and log in pass word I go the key board and type double tap letters and nothing happens they do not insert in to the user name field.
I've tried entering my user id in to the id.apple.com the qrz.com website and the credit karma site to name a few and I can't sign in.
it won't take my leters and numbers.
But I was able to sign in to I cloud from settings and set up my apple id on the phone and the key board works when I unlock the phone with my password.
its just in safari I think but I haven't tried it any where else.
I tried to do a reset and also a reset with all phone informations pictures etc.
well thanks for any help.
Has any one else have thes problem and is there a solution or should I exchange the phone?
Thanks
Carlos