AI in Photos doesn't seem to be working

Today I upgraded to 15.2 and immediately enabled AI in Settings, with the language set to English (US). I can use AI across most sections, but what I really wanted was to use it in Photos. Unfortunately, it doesn’t work. Not only is AI-powered search not functioning, but even basic searches (e.g., for objects like cars or dogs) no longer work. How can I check if Photos is indexing in the background? Activity Monitor didn’t provide any insights.