Spa water level dropping

Hi all, I noticed our spa water level was low, after we had used it the night before. The top step was dry. Ran the pump, brought the level back to normal. Days went by, and I noticed the spa was down again. I called our pool builder, as pool is less than a yr old. He came out and replaced the back flows. I saw that when he pulled the backflows from his truck, they were not boxed. So anyhow seems the problem was solved. Fast forward a month or 2, used the spa Sunday night, spa was down Monday by noon. Called pool builder, he suggests they cut out the existing backflow devices, and replace them with new. I guess I'm okay with that, it just seems a bit drastic. Any recommendations? By the way this would be handled under warranty. The original ones he replaced, the rubber seals were deteriorated.