Mixed Signals

Hi,
I’ve been reading the forums for a little while and have a situation of my own that I’d like some advice on. It appears this guy has lost interest but I would like some of your input.
I was talking to a guy on a dating app for about a month. We hit it off. He asked a few times to meet me. We finally settled a date and got together. There was definite banter, teasing, and smiles. We were chatting the whole time, no awkward silences.

That evening, he texted me saying I was super cool and even better than he expected. We texted the next two days, very normal, I felt good about it. Then I noticed he got quiet. He ended up texting me saying that he doesn’t mean to ignore me but it was starting to get a bit serious with someone he had been casually dating the last few months. This was definitely strange to me as he never mentioned this before. He left it off saying “it’s a complicated situation.”

I’m not sure what happened here. I will definitely move on, just wanted to know if you’ve ever experienced anything like it.

Thanks in advance!