This has happened to mine. Also, annoyingly, it’s an unusual shape and I can’t get a replacement for the seat or the fittings. I tried to find replacement fittings from shops and on the internet but couldn’t. I’m probably going to end up replacing the whole lot which goes against my zero waste policy. I couldn’t believe I couldn’t just get replacement fittings when one bit broke. The shop that fitted the toilet sold me their last replacement seat (it was slightly damaged but they refused to reduce the price because they knew I was desperate. We did try to fix the original fitting but, because it’s plastic, it just broke. I might be able to find a contact number of an internet company that helped me and I did see a universal fitting on the internet but that didn’t fit either.