Paddles seem to be the topic of the week, looks like it's delaminating a little bit and yes everything is porous, keeping it in a bag, wet is not a good idea.
My opinion would be, Sand it back and put another fresh coat of a epoxy over it.
Good as new

It's not good.. But it's just a look thing.. It should not effect the paddles performance.. and yes. I think it's from putting it in the bag wet.. For some reason these top coats sometimes are porous and absorb moisture .. Both boards and paddles.

But I'm thinking that if you washed and dried your paddle offer each time you use it that would not happen (not saying that you should.. even though I do.)

The finish coat has broken down, just a sand and re coat with a marine varnish , or 2 pack you can brush it on just thin it a little. To much sun and yes not good to put it in the bag wet.