Marks in PSA slabs

[trainerjack]

Made a thread asking a similar question a bit ago. The marks don’t look exactly the same to what are in mine, but maybe that thread can help.

Is this moisture in my PSA slab?

There is this white spot on the border to the left of the Pokeball here that I can’t tell what it is. Its not on the card itself because it shows up on the case when it glares as seen in the second picture. Anyone have any idea what it is? some of my other older slabs also have a little bit on the back. I have never had the best temp control in my rooms so could it be moisture? If so is there a way to fix it? Or are my cards technically damaged now? If anyone can help me I would really appreciat…