I feel like I did everything right and still messed up

I (M29) matched with someone (W24) and thought things were going well. I thought she was pretty kind and enjoyed talking with her about our past mistakes and hobbies. Our professions also seemed compatible because we both work with children/adolescents. She also admitted to being shy, which I liked because I can also be shy.

After texting for three days, I decided to ask if she would like to meet me in person, in a public place of course. When I opened the app a few hours after asking the question, I was distraught to find that she had unmatched from me.

I don't know what I did wrong. I did everything I heard I was supposed to do. I ask her about herself, and I demonstrated confidence by asking her out after a few days, which I heard is what people should do before the other person moves on to someone else.

What did I do wrong? Should I have waited longer? Let her ask me out first? Asked to have a phone call first? After I month on this app, I finally matched with someone I liked but completely blew it, and now I won't ever hear from her again.