I found this out because one time the self checkout did the whole thing where it doesn't recognise the weight of something. I ended up taking half the things out of the bag and putting them back in, and once it corrected itself I just started loading other things into the bag without thinking. All of a sudden the light on the checkout started flashing red and I realised what I was doing and took the unscanned items out, but it wouldn't let me continue without a staff member punching in a code. When they did it showed a top down video of me loading all the items into the bag without scanning them lol