I'm using the latest beta, but this has been an issue for me for...I dunno, months and months?
A couple of times a week, I will go to a web site's login page... I hit command-\, and .... nothing happens. At that point sometimes clicking the browser extension icon will pop up the mini window... sometimes nothing happens there either. Sometimes launching the 1P app will get things working, sometimes not.
At that point I have start 5-10 min of "1password debugging" where I restart the browser, restart 1p, sometimes restart my machine, etc. to get it working.
This happens in Safari and Chrome (the two browsers I use). It also happens on my Mac Mini at home (running the latest Catalina beta and latest 1p beta) as well as my work MacBook Pro, where I run latest official releases of everything.
1Password Version: Not Provided
Extension Version: Not Provided
OS Version: Not Provided
Sync Type: Not Provided