Email file attachment button in Safari not responding

Trying to troubleshoot this problem for someone else who is no longer able to use the paper clip “attach files” button when composing emails in Safari. This is happening in Gmail and Comcast accounts. The button does work in Chrome in both accounts. Browser is Safari 14.0.1. OS is Mojave 10.14.6. JavaScript is enabled in preferences.

Any ideas about what could be causing this? Thanks.

Pop-up blocker perhaps? It may be on by default, so try going to the settings for that website and turning it off and see what happens.

what happens if you allow all content in Safari on that particular site, through the per site settings?

Thanks. Neither of those fixed it.

As far as I can tell, this began with the update to Safari 14. I’m stuck. I think I’m just going to have to wait until Google turns up more results of people asking about this same problem.