Lid Issue

Submitted to Product Chat

I have 4 of these Rust-Oleum Restore Semi-Transparent One Coat cans still with the clips on them that I received from Rust-Oleum last summer.  They are stored in our garage year-round.  I noticed a couple of days ago that the lids were starting to open up, and a couple of the cans had their bottoms bulging.  All the lids are a plastic material.  Any clue what's going on?  Should I toss them?