I've observed for quite some time and some versions and 1Password on Windows will not always immediately save to my.1password.com after making changes to my passwords.
I am using system-wide proxies via Internet Explorer's internet settings → Proxy Server, and have set HTTP, HTTPS and SOCKS proxies.
After making changes to my password, I wouldn't be able to view them on iOS and Mac, because they had not been up-to-date.
Most of the time I had to close 1Password for Windows completely and re-enter Master Password, then opened 1Password app window to make the sync.
This has been painful.
I hope the sync mechanism will be as good as it is on both iOS and Mac. Or at least provide an option to manually force a re-sync placed between LOCK and MINIMIZE.
1Password Version: 7.3.654.BETA
Extension Version: 18.104.22.168
OS Version: Windows 10 1809 17763.195
Sync Type: Subscription