Hello Bailey997,
You should be able to search for loops using the methods below:
• Click the Button View button
to see the category buttons. Click the category buttons to access the keyword buttons for that category. You can also Shift-click multiple categories for more keyword buttons. Then click the keyword buttons to see the matching files in the results list. If a keyword is dimmed, there are no loops that match that category. Your current selection appears under the name of the category button.
• Click the Column View button
to see a standard macOS column file directory that is hierarchically separated into All, Favorites, Genres, Instruments, and Descriptors search criteria. Select a keyword type in the left column, select a category in the middle column, then select a keyword in the right column to see the matching files in the results list below.
• Click Loop Packs at the top of the Loop Browser, and in the pop-up menu that appears, choose the Loop Pack or folder with the loops you want to view.
You can also find those steps in this resource: Search for Apple Loops in GarageBand on Mac - Apple Support
Should you still be unable to locate an expected loop, you'll want to reach out to Apple Support so they can look into your particular situation further: Contact - Official Apple Support
Take care.