Dash and dine

Maybe your bill-paying process was a huge turn-off.

Why didn't you just pay at the table?

Something between the intro when she said she was glad for the second date and the end at the restaurant when you were paying went wrong. Think back, did you monopolize the conversation talking about only yourself? Did you do or say anything rude to or about anyone else during the service and meal? Did you ask reasonable but general questions about your date to show you were interested? Do you chew with your mouth open? Did you get wound up talking about politics?

There is one more possibility that might explain this in case nothing negative happened - Maybe she saw her current boyfriend or husband and had to duck and disappear. If that were the case you are better off not getting involved.

Maybe she just does this to get free food.

It could easily just be her wanting free food.

don't do dinner dates for the first couple. something small like coffee where you aren't spending a lot of money. these days women use apps like tinder, etc to get free meals more than anything.

Yup, she was gone for her second date that night. You were contestant #1 and now is time for #2

or she just didnt want to hurt OP's feelings.

And disappearing when the check comes due is SO MUCH MORE comforting...

I’m sorry that happened. :(

Sounds like she's fake AF and you're better off without her.