Alert Tone purchased from iTunes Store shows up under Ringtones instead of Alert Tones

Hi,

I bought the WhatsApp alert tone from the iTunes Store and added it to my iPhone 14 Pro Max (iOS 16.3.1) where the system saves it in the "Ringtones" section;

Instead of in the "ALERT TONES" section;

When I open up WhatsApp and go to Notifications > Sounds (within the app) it only allows me to choose from the "ALERT TONES" list;

Therefore I can't select my purchased WhatsApp tone as the alert tone, which was the point of the exercise.

Why doesn't Apple's ecosystem download the purchased alert tone into the correct area?

There is obviously some sort of internal system delineation where it divides Ringtones / Alert Tones into 2 x separate lists for the pre-loaded standard system tones, why can't it properly discriminate what the purchased/downloaded tone is?