We have very long hot summers down here, which probably wreaks havoc on the seals when followed by cold wet winters (my gear lives permanently outside in an observatory). I’ve had two instances of ‘fogging’ this year, which have been remedied by replacing the desiccant tablet (after baking). If you’re interested, the Atik procedure is here:
https://www.atik-cameras.com/question/revive-old-desiccant-tablets/
Paul