At https://appstoreconnect.apple.com/, I have the Admin role (but not Account Holder).
At first, I had the Developer role. When it got switched to Admin, the buttons on the website that only admins should see (for example, the add app button), still weren't visible to me immediately, but I started seeing more of them within 24h.
Now, I can click the add app button (see first screenshot) but when I click the link to add a bundle id (the link is called Certificates, Identifiers & Profiles), it says that I don't have access (see second screenshot).