1Password desktop not syncing

Recently discovered that 1Password (latest version) on MacOS 10.14 won’t sync–I’m using Dropbox–unless the app is completely quit (control-option-quit) or the entire system is restarted.

I’ve attempted to get help from AgileBits, but as soon as I mention Dropbox they gently ask me to go to the membership version–I’m using the paid-for standalone version–and tell me there’s nothing more they can do.

Anyone else notice this? Here’s a recent screenshot of the 1Password Sync preference pane: