i have got the same problem for the storage expansion, even on a lower level. i had 520c, full kernel stock, then bought an expansion for 500c, but somehow im at -480c
Just have to suck it up and be aware of it for now sadly - balancing is different than it was intended, but you know of it now and it's just like that
Or in other words, don't push for storage upgrades unless you can comfortably afford it with plenty of money to spare
