In the last version (I guess) it was working. In the new 1Password Alpha 22.214.171.1240 there is this strange bug:
The letters in these boxes are missing. But if I tap on lets say the third in the first row, it leads me to the c. But the c won't show up in the blue box.
Device: Nokia Lumia 830
1Password Version: 1Password Alpha 126.96.36.1990
Extension Version: Not Provided
OS Version: Windows Phone 8.1 Update 2
Sync Type: Dropbox (.opvault)