(Please note I won't respond to direct/private messages or be drawn into dialogue, it's intended to be a helpful post only) I work for an online supermarket and slots are booked for the next 3 weeks across all retailers - I suggest if you see a slot, even if it's 3 weeks away, secure it now so you know you have something in the future. It may not seem like it but supermarkets and manufacturers really are doing all they can to keep food moving through the supply chain and on to the shelves. I'm not aware of any that prioritise an online shopper over a store shopper. but some postcodes, especially in London, may have online orders picked from a dedicated 'dark store' therefore not being picked from a shop. Websites and apps are very slow due to the volume of online traffic so if you're asked to wait in a virtual queue before you can start shopping, it will be because they're trying to move customers through checkout without it crashing - online shopping will take much longer than normal, which is tedious, but a cuppa, classic fm or an audio book could help. Substitutions and missing products will be very common and you won't always get what you were after. - if items you normally have are no longer visible on the website, it's because they've been removed from the assortment - if an item is showing as out of stock but still visible, they'll be hoping to get more stock in - and if it's showing as in stock but is subbed or missing when delivered, it's unfortunately a case of when your order was picked, it had all gone Thank you and look after yourselves
