Why isn't my lifetime learning credit being applied to my refund total?

That credit is not refundable.  It can only reduce your tax owed down to zero.  It is not added to your refund.

https://ttlc.intuit.com/questions/3262984-who-is-eligible-for-the-lifetime-learning-credit

The Lifetime Learning Credit (LLC)is a non refundable credit.  It can only be used to reduce your tax liability. It is not added to your refund. Note that it goes on line 20 of form 1040*.

* From form 8863, to Schedule 3 then to line 20 of your 1040. 

The Lifetime Learning Credit is a nonrefundable credit.  This means, it can lower your tax liability to $0, but will not result in a refund if you did not have a tax liability to start with or did not pay taxes in or have taxes withheld to be refunded . 

To see if you did receive any portion of the Lifetime Learning Credit look at Schedule 3 line 3.  

You can see your schedule 3 by clicking the following: Tools>>Tax Tools>>View Tax Summary>>Preview My 1040>> then scroll to your Schedule 3