Travelled with Wizz from Cardiff to Crete recently. We were unable to check in online due to problems with their app and they blamed it on being part of a package purchased via onthebeach. Numerous phone calls and emails at high cost to eventually be credited with airport check in on way out , check wizz air reviews. They wouldn’t do way back so we had to pay an additional £69 for that joy or waste a day of our holiday on the phone.