Sorry for the delay in getting back to you on this. The problem is often intermittent which makes spotting patterns a little trickier.
From my testing, it's clear that the sync is broken between 1Password,com and the "1Password for Safari" v2.1.3 extension.
Updating an item in either 1Password 7.9 or the early access 1Password 8 syncs immediately to 1Password on the web. I can literally see it update on the web instantly as soon as I click Save in either desktop app.
Whether that change makes it to the "1Password for Safari" extension is hit or miss. Sometimes it will work almost instantly. Sometimes it won't and requires toggling of the "Integrate with 1Password App" setting, and then I have to wait 30 seconds or more for the extension at the Loading... screen.
Even toggling the setting doesn't always trigger the update. I can click the Edit button in the "1Password for Safari" extension, which takes me to the 1Password website to edit the item, make a change, Save, switch to the Safari extension and no changes show up.
Frequently, the "1Password for Safari" extension will just sit at the loading screen with spinner for ages (30 - 60 seconds, even longer sometimes) before allowing me to use it.
In my latest test, I updated an item at 07:37 and the change took until 07:54 to show up in the "1Password for Safari" extension, and only did show up after I turned the "1Password for Safari" extension off completely in Safari preferences, and then turned it back on again and logged-in (after the obligatory minute or so wait on the loading screen).
It's very frustrating and makes the "1Password for Safari" extension completely unusable for me when it's playing up.