On a prior 5er, the pedal started to immediately open the hole as well as the bowl not holding water. The fix was to tighten the bolts compressing the seal better (additional resistance on seal would allow bowl filling function to work without opening hole, and additional compression sealed better). Worked for few years after tightening until we traded in.
On our new 5er, I let the bowl dry out when storing and it started leaking (not holding water). I cleaned seal and lubed with vegetable oil. It worked fine again. Since then (a year or more ago) when storing for more than a couple weeks I empty and place 1/2” of vegetable oil in toilet. It doesn’t evaporate, and keeps the seal lubed. Working great.