Depending on where you're based, you'll find PayPal's new data-sharing option under a different name. Remember, you may not see this at all if you're based in a country that doesn't allow it.
If you're in the US, you should head to your profile Settings and tap on Data & privacy. Under Manage shared info, click on Personalized shopping. You should see the option enabled by default. Toggle off the button at the right to opt-out.
If you are in the UK like me, you'll see something different after you head to your profile Settings and tap on Data & privacy.
Under Manage your privacy settings, here you'll see an Interest-based marketing tab – click on it. At this point, two options will appear: Interest-based marketing on PayPal and Internet-based marketing on your accounts. You have to tap on each of these and toggle off the button at the right to opt-out. These instructions can also apply if you're based in the EU.
Is your account location set in GB?
Mine is in Germany and opted out. But I think remembering that there was already a post quite some time ago about the same thing.
Address is Ireland. No location set in the location section (under name in profile section), but my address is clearly set.