This normally occurs when a new liner has been purchased or replaced under warranty.
This is nothing to worry about. New liners need a little time to expand before they reach their full size. The vinyl material the liner is made from takes approximately 6-8 weeks to fully expand. The rate at which the liner expands depends on the ambient air temperature and how warm the water is heated. We apologise if your replacement liner is not as aesthetically pleasing as your previous liner. However, it should look the same once fully expanded.
If the 8 weeks have passed and the liner is still to small please contact our Customer Care team below.