I Had it on my 2022 Sportage, after reading several other owners had the same problem i was gutted, i wanted to be unique and be the only person ever to have a faulty cap that wouldnt fit flush against the rest of the bodywork so I took it back to where I bought it and told them about it, to my surprise i didnt have to book it in and come back in a month`s time, the service manager said they could fix it straight away, make yourself a cup of drink and get comfy, literally about 45 minutes later my car was back outside and keys were handed back to the girl on reception, then both me and the service manager went outside and inspected it and it was as i imagined it to be, a snug, flat fitting fuel cap, I asked how did they mend it, he said it`s to do with where the rubber filler pipe fits the metal neck of the fuel tank, for some reason when they fit it in the factory they dont tighten it up and as the vehicle was driven around with fuel in it the tank it moves about a bit till it settles down and because the pipe fixings aren`t tight it pushes the filler pipe against the filler cap forcing it out, al the technician does is relocates the rubber filler neck over the metal neck and tightens it up, never to be taken apart again i add!!