"Limit already reached" error after future date set then return to current date

Avoid duplicates

• Bug is not mentioned in the FAQ
• Bug is specific for Android only, for general issues / questions that apply to iOS and Android please raise them in the documentation repository

Technical details

• Device name: Samsung Galaxy A52 5G (SM-A526B/DS)
• Android version: 12
• App version: 2.22.1
• Issue continues unresolved in version: 2.23.2

Note: The issue is not reproducible on Android 8.

Describe the bug

App does not stop exposure check taking place when date incorrectly set to future before installation. After correcting the date the app risk tile first shows the error message "“Exposure check failed.”. This changes after an hour to a green risk tile. After a further 5 hours have elapsed the error “Limit already reached” error message appears. This error message continues to show, even into following days, until the device’s clock has progressed to reach the original future date.

Steps to reproduce the issue

1. Set device date to two days into the future
2. Uninstall CWA (if already installed)
3. Install CWA
4. Open CWA
5. Tap “Let’s Get Started”
6. Tap “Next”
7. Tap “Activate Exposure Logging”
8. Tap “Turn on”
9. Tap “Next”, tap “Next”
10. Tap “Do Not Share”
11. Tap “OK”
12. Tap “Allow”, disable optimized battery usage for Corona-Warn (device specific)
13. Dismiss QR Code Scanner pop-up by tapping on “X”
14. Note “Exposure check failed, with timestamp Today”
    
15. Tap “Restart”
16. Note that this does not change the status
17. Leave CWA open and set the date correctly to today (or automatic)
18. Tap “Restart”
19. Note “Exposure check failed, with timestamp of previously set future day”
    
20. Close and re-open the app at hourly intervals. If “Exposure check failed.” appears, then tap “Restart”. Two hours after initial installation, a green Low Risk tile is shown. (Alternatively just wait for 5 hours.)
21. On the 6th re-open an error message appears: “Limit already reached”.
22. (Android) Settings > Google > COVID-19 Exposure Notifications > three-dot symbol > Exposure checks shows 5 checks from the current day and one check from the future day.

Open the app again the next day. The error message “Limit already reached” still appears.

Expected behavior

• The app should prevent an exposure check from taking place if the date does not match the server date.
• With the “Exposure check failed” status an error message should be shown that the reason for this failure was an incorrectly set time.
• Also, if an exposure check is allowed to happen, then the app should recover and start carrying out exposure checks when the date is corrected.
• If “Limit already reached” appears, then this condition should clear automatically after 24 hours.

Additional information

• Recovery is possible by resetting the app
• To clear the wrong exposure check history in the Google log it is necessary to uninstall and re-install the app
• There is no FAQ article covering this situation. https://www.coronawarn.app/en/faq/results/#limit_reached says the device will recover after 24 hours
• Google Exposure Notifications API modes documentation specifies provideDiagnosisKeys quota - Six per day (counter resets at 00:00 UTC)

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Internal Tracking ID: EXPOSUREAPP-9077

[mtwalli]

@MikeMcC399 Thanks for the feedback, Unfortunately I can’t share the whitelisted account publicly. Probably I can provide a signed testing APK with the first RC of 2.27.0

[mtwalli]

@MikeMcC399 I opened a PR linked above to potentially fix these issues, can you verify if it resolves them?