Genmoji doesn't recognize all people in my camera roll

I have about 10+ unique people and animals labeled in my photos in my camera roll, however, it appears that Genmoji only allows me to pick from a select few. I have seen this as a common issue online, but even being updated to the latest iOS 18.4.1, it still is not updating the Genmoji and Image Playground apps.

Last night, I randomly got a pop-up in Image Playground below "Choose a Person" that said "Finding People... Image Playground organizes people when iPhone is locked, charging, and connected to Wi-Fi". Sure enough, I woke up and saw that it gave me a few more people to select from as options in both Image Playground and Genmoji. However, it wasn't everyone. I'm not sure if this is a bug, but it is a bit frustrating to not be able to use the feature as intended and nobody can offer a solution.