App notification confusion

[louderthan]

My mum and I went to an art exhibition on Wednesday. We both checked in on the app. She has not checked in anywhere else since.
Tonight she's received a notification telling her to isolate for 12 days. I have not received anything. I am baffled! Where has 12 days come from and why have I not had a notification? Has anyone else experienced similar?
I'm living with her at the moment so I will need to self isolate as well obviously but it really doesn't inspire any confidence in the efficacy of the app.

It doesn't only work from checking in. It also links to other phones using Bluetooth. When someone inputs their test result on the app it will check for other phones that were close enough for a long enough time to count as a close contact and then notify them.

If it says 12 days then by the time the positive result has been received and input on the app 2 days of the 14 days have already passed so less time for her to isolate

You dont need to self isolate if you haven't been told to. You may not have had contact with the same person

I've just checked and she has bluetooth on so that could be an explanation.
But realistically I will have to isolate as we have been sharing a small house with one bathroom, sitting on the sofa together etc for the last month so it seems like too much of a risk not to....

Do you not have Bluetooth? That's how the app works.

The main premise of the app is Bluetooth tbh.
It's up to you if you isolate as well but you don't have to

Without bluetooth the app is useless except to check in. You should be leaving bluetooth on. Turning it off renders contact tracing useless, I admit I didn't realise at first either.

I had a notification on Thursday so I had to isolate for eight days. It was either because it took somebody a long time to get a positive test result after I had interacted with them, or more likely because they change some of the algorithms on Thursday and I had had a lower level of contact than they were previously notifying for. I have no symptoms and my partner isn’t isolating. Hope your mum is ok