Unable to copy suggested passwords from Safari on the Mac

Thank you for the reply.

I ran through the four steps that you've shared. I can now copy the suggested password in most other websites. Sadly, gitter.im still doesn't work.

When I try to reset my security passphrase in gitter.im, I can't copy in 1Password's suggested password. When I enter a password myself and try to have 1Password copy it, it doesn't work either.