Why don't previews in push notifications work properly?
On Android (all app versions) and iOS (Threema version 2.9.0 and up), incoming messages can be decrypted in the background and presented along with a preview in the push notification. Push preview must be enabled in Threema settings for the preview to be shown.
If there is no Internet connection immediately after a push notification has been received, it is possible that no preview can be shown.
No preview will be shown on Android if:
- the master key is locked, or
- PIN protection is activated, or
- background data is restricted
A sender's name (as saved in the contact list) is not visible in push notifications on Windows Phone due to technical limitations of the operating system. On iOS, if there is no Internet connection immediately after a push notification has been received, it is possible that the real contact name cannot be shown.
If the real contact name cannot be shown, the “public nickname” is displayed instead. By default, it assumes the value of the user's ID, but can be changed anytime. You can ask the sender to use e.g. his or her first name. This will help you recognize the sender of a message.