WLAN Server sync does not sync additional Vaults (only Primary one).
I'm familiar with https://support.1password.com/wlan-server/ and https://support.1password.com/wlan-server-troubleshooting/
WLAN Server on 1Password 7.3.6 on iOS is broken (vaults are sync without problem on iPhone 4s).
What more info and what diagnostic files do you need from me to fix this issue?
Have a nice day
1Password 6.8.9 (689001) on macOS 10.14.6 on MacBook Pro (15-inch, 2018) (family pack license)
1Password 6.8.9 (691001) on iOS 9.3.5 on iPhone 4s (pro features purchased)
1Password 7.3.6 (70306001) on iOS 12.4 on iPhone 6s (pro features purchased)
1Password 7.3.6 (70306001) on iOS 13.1 on iPhone 6s (pro features purchased)