Not smashing and her saying I think you will?
All of it
Date went "well". You don't even seem too hype about the date yourself. Like it was good but nothing special. I'm sure she felt the same if not worse, cause women date more.
Things seeming to go in your favor... It wasn't painfully obvious cause she wasn't feeling it. Women who like you and want you, are damn near goofy with the way they go out their way to show it. Or mention it. Or make sure you know. Especially on the second date
You don't smash... Clearly.. It's 2021. You talking in between dates too. You known her a few weeks probably. Maybe more.. And all you get is......
A goodbye kiss. Not a hello kiss though. Not a kiss throughout the night. But a goodbye kiss... Which would be ok if......
"I think you will" didn't come next. Again. More indirectness. Playing coy. Keeping her options open.
I'm not trying to be a dikk. She probably was iffy. But whatever you did or didn't do in that meantime, is why you getting ghosted. She's not thinking about wasting more time and another night to maybe start really feeling you. Like I said before, they're used to dating. She probably got other nikkas lined up. She single, why not. She's moved on.
Do the same. It happens to us all fam. Start seeing the signs early and stop wasting money/time. Cause if she wanted to, it seems she could have good night kissed you at least for two more dates, on your dime