Anchor not working

Anyone else having a problem of #anchor's not working?
I set an anchor via the flag icon in the editor, and then link to the anchor via the link icon in the editor, but when clicking the link, the page URL changes to the correct url (whatever.com/page#anchor) but the browser does not move down to the correct position.

"top" appears to be a predefined anchor that DOES work when linking text to #top but none of my other anchor references are working.