I pay for Ultra Netflix BUT TMOBILE can NOT let me use it

Netflix changed the rules to prevent password sharing outside of the primary residence.   This is not something that only affects our T-Mobile Netflix on Us subscription.  It affects all Netflix subscriptions.

One of the Netflix rule changes is that accounts paid by a third party (like T-Mobile) are not eligible for additional members. I have no idea why Netflix made that restriction since it makes our Netflix on Us accounts much less valuable.  Maybe Netflix wants to eventually eliminate third party accounts, and this is a first step towards that goal.  

That restriction is what you are running up against.   Your daughter can't use your account when she is at college because of the new password sharing restrictions, but you are not able to add her as an additional member because the account is paid through T-Mobile.

T-Mobile can’t add your daughter as an additional member either because of the Netflix restriction on third party accounts. 

There is nothing T-Mobile can do unless they negotiate a new agreement with Netflix.  Netflix changed the rules.  Unfortunately, that means that currently you have just two options:

• Purchase a separate subscription through Netflix (not through T-Mobile) for your daughter.
• Cancel your Netflix on Us from your T-Mobile account.  Then purchase a new subscription directly from Netflix and add your daughter as an additional member.