I jokingly posted a screenshot of a dating app profile I saw on Instagram. She saw it and said it "rubbed her the wrong way". She didn't like that I would take a pic of someones profile (there was nothing in it that would identify the person) and post it. Ok, I can admit its a little dickish, but its not really that serious. You don't just cut things off cold turkey for that. It would make a lot more sense if she just lost interest or met someone else but I didn't get any indication of that. It was very sudden. It was all good, she was initiating communication, and then 2 days later this.

Basically it went like this:
"seems like youre upset about something"
"this is over"
"why?"
"you posted that picture. bye"

🤷‍♂️