Hi all, would it be fair to say we are reasonably confident the problem is that Google Maps / Chrome / Chromium is not conforming to web standards, and Firefox is?

This is about how Firefox interprets the disabled attribute according to web standards. For Firefox the mere presence of this disabled attribute is sufficient to disable this button (i.e.disabled="false" doesn't work), so in Firefox the only workaround to make this work in the current situation is to remove this disabled attribute using a bookmarklet or otherwise.

Thanks for the info. I think I will leave this thread .