I sell a few things on vinted, fewer since they've limited the postage options you can use without a printer but the last few things I've sent the buyers haven't marked as received, even after I've politely messaged them. Whenever I buy anything I mark it as soon as I've got it, as you're supposed to do!
The parcels are tracked so I can tell they've been received, presumably there's nothing wrong as they haven't replied to my message and I haven't had any notification of a dispute from vinted, so why not just click the button??? I know it is a very minor issue but it's annoying having to wait 3 weeks for vinted to progress it automatically, and if you've sold a few items to keep track of everything, while wondering if there's going to be an issue you'll have to try and sort out, when it's so easy for the seller to just click that one button!
Also why is the delay for vinted to automatically mark it so long - surely a fortnight after delivery is more than enough time for someone to raise an issue, not 3 weeks!