Phone numbers in Identities do not sync from iPad to Mac

Here's my setup: 1Password on Mac, 1Password on iPad1, Dropbox sync set up and working ok except for this scenario. Latest versions of 1Password, Dropbox, and iOS.

Here's the scenario:

1) Add a new identity on iPad. Give it nothing but a name (call it "Test"). A few seconds later, it shows up on the Mac. OK so far.
2) Edit "Test" on iPad by adding an email address, "test@home.com". A few seconds later, the update shows up on Mac. OK so far.
3) Edit "Test" on iPad by adding a home phone, "123-456-7890". Wait. Wait. Wait. The update never shows on Mac.

The problem appears to be with the Home phone field (maybe others, haven't tested). Here's another couple of similar scenarios:

1) Add a new identity on iPad. Give it a name and email address. The new identity quickly shows up on Mac.
2) Add a new identity on iPad. Give it a name and a home phone. The identity never shows up on Mac.

Sync in the other direction (Mac to iPad) seems to work ok.