>How to opt out of personalized ads
Open your device's Settings app Settings app > Google, or open the the Google Settings app (differs depending on your device). Under “Services,” select Ads. Turn on “Opt out of Ads Personalization” by moving the switch to the right until it turns blue. Note: If you clear your cache, you'll lose your opt-out setting.
Especially that note at the bottom. What cache? Why is this setting only in a cache?
https://www.cashify.in/how-to-clear-app-data-and-cache-on-an...
I'm not sure why it would be in cache and not data though.
Edit: More context on Data vs Cache: https://android.stackexchange.com/questions/108926/what-is-t...
It seems arbitrary and they could have included it in data if they wanted to. That said, I don't think the cache will ever be cleared automatically so probably not a huge deal.
Perhaps not getting tracked could be seen as a bug that clearing your cache would fix? /s
It means it's not synced to the server or your account for whatever reason. If you nuke the Play Services storage as a user, the setting (like all other local files and settings for that app) will get deleted and reset.