My vault contains a bunch of attachments. Most are in secure notes, some are on other types of items (passports, etc.). The Android client however does not show any of them. I have no issue with the iOS and macOS clients. This was recently an issue while traveling abroad when I needed access to a photo of a document stored as an attachment in 1password.
1Password Version: 6.5 BETA 7
Extension Version: Not Provided
OS Version: Android 7.1
Sync Type: 1password.com