I believe some of these issues were on very early production cars. Remember that Lotus had been partially building, and stock-piling parts for months when the supply crisis was going on. They couldn't get all the parts needed to build a complete car, so parts sat around a lot longer than normal, which would have given body panels a lot of time to be exposed to damp weather and conditions.
They're now producing 20 cars a day according to a tour visitor who asked (can't remember who it was, but it was recent) so their JIT system appears to now be working properly. This means parts arrive and go straight to paint and assembly in a very short amount of time, so there isn't time for parts to sit around unpainted to be exposed to moisture. Unless we start seeing some of this on recent production cars, I would say this is probably something only a few of the very early production cars might see.