sensors are all junk, if I start getting a puddle of water in the bathtub I know I'm full usually after 4 days/2 people. Dishes are washed outside clumsy me always spills the dishwater on the ground trying to carry it inside.
New unit may be miswired from the tank to the display. Many tank sensors are just bolts thru the tank side at different levels with a wire to each sensor from the display. Find the brand name of your sensor and get the installation manual (Google it). Compare wire colors at each end.
Your dealer will be happy to to this under warranty -- maybe in 3 or 4 months when his shop has an opening. DIY is always best.
2006 Roo 23SS behind a 2017 Ford Expedition