Can someone explain this phenomenon to me?

I drink like once a month and we get rum 90% of the time. We had a small gathering yesterday and we got this brand of rum we always get and it always gets us drunk. But this is something I’ve noticed a few times and it happened to me yesterday too. I had a couple of drinks, started to feel a light buzz and then we all just walked around and talked. After a while, it started feel like I was sobering up. After that, no matter how much I drank, I couldn’t get drunk again. Idk how to explain that feeling. I just felt down. Not down like, I was sad, just low on social energy, if you know what I mean. I just sat there having small conversations like my normal self. I went for 2-3 rounds after that but just couldn’t get drunk again. And this IS something that has happened to me a few times. Any idea what this is?