ENF shared two possible Encounters, but only one is shown in iOS App

[svenkubiak]

Avoid duplicates

• Bug is not mentioned in the FAQ
• Bug is not already reported in another issue

Describe the bug

On 03.08.2020 the iOS App started to show me 1 possible risk encounter (low).

Today, I received a notification from ENF that 2 possible encounters have been shared with the App, but the App still shows 1 Encounter. I am checke the App every 24 hours for manual update, so I would not have missed a second possible encounter.

I double checked all "Begenungsüberprüfungen" protocols and I can only find 1 possible Encounter as it is shown in the App.

Any idea what happend to the second encounter and why is it not shown in the iOS App?

Expected behaviour

Number of possible encounters from Notifications from ENF and in iOS App match.

Steps to reproduce the issue

Technical details

• iOS Version: 13.6
• Device: iPhone 11 Pro

Possible Fix

Additional context

[Ein-Tim]

This should be related to this point in the FAQ.
You had contact to two people who where tested positive for COVID-19, but with only one of the two you had contact for longer then 10 minutes or/and you were closer than 8 meters.

[Ein-Tim]

I double checked all "Begenungsüberprüfungen" protocols and I can only find 1 possible Encounter as it is shown in the App.

Do you mean you went to Settings and checked it there (Privacy->Health...)?

[daimpi]

You had contact to two people who where tested positive for COVID-19, but with only one of the two you had contact for longer then 10 minutes or/and you were closer than 8 meters.

@Ein-Tim No: if he had contact with one of them for more than 10 min & closer than 8 m, the app would not show a "green/low" risk status, but rather a red one, so both encounters (if there were actually two) must have been low risk

The weird thing is that iOS thinks that it had 2 encounters, while CWA only shows one.

[svenkubiak]

I double checked all "Begenungsüberprüfungen" protocols and I can only find 1 possible Encounter as it is shown in the App.

Do you mean you went to Settings and checked it there (Privacy->Health...)?

Yes. Did an export as well.

[Ein-Tim]

@Ein-Tim No: if he had contact with one of them for more than 10 min & closer than 8 m, the app would not show a "green/low" risk status, but rather a red one, so both encounters (if there were actually two) must have been low risk

You're absolutely right, my fault.

The weird thing is that iOS thinks that it had 2 encounters, while CWA only shows one.

Yes, that has to be investigated.

[Ein-Tim]

@daimpi
If @svenkubiak checked all protocols in the settings and found only one Encounter, the App shows the right number of possible Encounters, or not?

And that Apples Push Notification showed 2 Encounters is an issue/bug from iOS and not from CWA...

Correct me if I'm wrong

[Tho-Mat]

Other Possible reasons:
Two contacts to the same key
One contact is more than 14 days old now
Bug in Protocol

[Ein-Tim]

One contact is more than 14 days old now

I also thought about that before, but the Push Notification says "Wöchentliches Update" so my understanding is that both (if there were 2) contacts, happened in the last 7 days.

[svenkubiak]

For reference, this is the protocol export matching one encounter (starting 03.08.) which results as one low risk encounter in the app.
ExposureChecks-2020-08-05.json.zip

If @svenkubiak checked all protocols in the settings and found only one Encounter, the App shows the right number of possible Encounters, or not?

Protocol and App match. Yes.

[Tho-Mat]

The message does not say the contacts happen in the last 7 days. It says it founds 2 contacts in the last 7 days. That is something different.
If a infected user publishes his keys, he publishes 1 to 13 keys (yesterday to 14 days ago).
So if 2 contacts were found in the last 7 days it could be they happened 20 days ago.

[thomasaugsten]

I assume the weekly report sums up every MatchCount in the ExposureChecks JSON of the last 7 days until the weekly report is created. Because this is the sum of matches the API response to the App requests. The API cannot say which matchcounts are the same maybe this is the reason why they sum up every MatchCount. But there is no official documentation from Apple side.
This means the MatchCount in the JSON and in the App are the same.

[svenkubiak]

I assume the weekly report sums up every MatchCount in the ExposureChecks JSON of the last 7 days until the weekly report is created.

Then the iOS notification should have said 3 and not 2, because at the time I received the push notification the sum of every MatchCount was 3.

[Tho-Mat]

Due to a bug in the protocol you only have the last 100 checks. For full Protocol you should have ~14*14=196 entries. So there may be missing some days entries. Hopefully the app gets its values from ios and not from the protocol.
That has to be checked.

[Tho-Mat]

@svenkubiak
No. 3 times the same hash file value. So only one contact