We just installed 4.0.2 for our Xenforo site. From a Windows client, I can see the icon from both Chrome and Edge. Using a MacBook, I can see the icon in Safari, not Chrome. Chrome has been restarted, but still no icon for AC.
I can also see the icon from an Android tablet (using Chrome), but it is not seen from Android or Apple phones.
Also, the features indicate a user can hide the icon, I cannot find where that can be done.
Am I missing some configuration steps?