On both Mojave and now Catalina, I don't get prompted for TouchID authentication when I invoke 1Password (command period) in Firefox. It works correctly in Safari. I have to type my master password and it stays cached for about 30 minutes and then I have to re-type my master password again.
1Password Version: 1Password 7 Version 7.3.2 (70302003) Mac App Store
Extension Version: 1Password X version 1.16.2
OS Version: 10.15
Sync Type: Not Provided