So. My Dometic 320 elongated porcelain toilet (longest name ever) is not working correctly. The pedal opens the drain but it does not pop back into place. I have to lift the pedal to close it & even when I do, the water continues to run to overflowing. Is this a fixable part? I spoke to a parts specialist & was told the whole thing needed to be replaced. My hope is that because I’m a greenhorn, I didn’t explain correctly & it is actually replaceable. Anyone else had this issue?