I talked to my friend who’s an electric engineer and worked with LCDs before about this issue. He said that the above answer from Elektron support had been a bullshit. In his opinion they just applied poor quality LCDs on the devices which can loose certain conditions very easily (he had some guesses about what might happen in such cases). But he definitely doesn’t think this is the normal behavior of those screens.
I can’t add to this story anything as I’m out of this technological territory. The only reference point I have are those many “old-fashioned” mini video games from my childhood which also had similar basic LCDs and they lasted for so many years (even a decade) without such issues.