On Day 4 I visited Patricia by the pool and asked for a custom nickname. When I submitted it, the main character introduced himself with the text from the first day, and Angelica came round to visit and introduce herself!

Hi, thank you for reporting this.

I updated the game with a fix that I tested and it works just fine now. funny enough, that was also a way to get infinite affection gain with Angelica - if one wouldn't mind all the introductions :D