IFixit Pro Tech Toolkit Rusty bits

I have purchased my Pro Tech Toolkit quite a while ago and its been one of the best purchases I have made. Recently when opening it up tho, I noticed that a lot of my bits are very rusty. I have never really noticed it before, but I feel like it might start affecting usage for some of the smaller bits.

Has anyone experienced this too? Is there a good solution for this?

I dont feel like I have abused the bits nor do I store them in a special environment. Its just my room next to my tech workbench. Not very moist, not very dry. Normal Austrian room.

Interestingly lots of other stuff in here isnt rusting either, so I am quite confused on how the bits managed to get so bad.

Thanks in advance!