You have to opt in to have your phone do this.
Are you sure you don’t have to opt out/disable?
It’s off by default.
“ Exposure Notification is a feature that's off by default in iOS 13.5, and actually using the API requires you to download an app from a verified health authority. Many countries are developing country and state-specific apps that users can download.Without an app that you explicitly download and opt in to using, the Exposure Notification API on the iPhone doesn't do anything at this time. Once you've downloaded an app and consented to using it, the Exposure Notification feature will become active on your smartphone.” — Apple's Exposure Notification System: Everything You Need to Know