Was I wrong about splitting expenses with American girl?

I recently ended a long-distance thing with an American girl after a trip together that made me realize we were too different, especially financially.
I’m from Portugal, she’s from the US. Before the trip, I assumed we’d generally split expenses or take turns paying. During the trip, money became a huge source of tension. She felt I was making her feel bad about the money I was spending, while I felt she expected me to cover far more than I was comfortable with. I was covering it all basically and she said that’s how it works in America. The man pays for everything.

She ended up leaving the trip early because she didn’t want to be in that situation anymore as I wasn’t paying for her stuff anymore, and buying an extra flight. After we got home, we eventually ended the relationship mutually.
The issue now is that I believe she owes me for expenses I covered during the trip, which she told me she would pay, but she kept dodging it for weeks. I told her I wanted to settle things and asked for the money. She refused, saying that before the trip I had told her that because she was travelling so far, I would take care of everything else, and that there was never a clear agreement about what she would pay for. I remember the situation differently.
She did agree to send me all the photos from the trip, which I had repeatedly asked for, and said we should go our separate ways afterwards. Shortly after that, she blocked me.

What makes this especially frustrating is that money was one of the main reasons the relationship fell apart in the first place. I’m now wondering whether I was completely unreasonable for expecting us to split expenses, and whether I should just accept that I’m going to lose the money and learn for the next time.

Was I wrong here or does it just show we are incompatible?