Epoxy 'fractures' on a stand up board - repair ideas

After having my board out today (about it’s 7th time on the water) i noticed two cracks in the epoxy. Both of them are in locations that would be difficult to have causeed by hitting them with the paddle. My guess is that they are ‘stress induced fractures’. Both look like cracked glass. One is on the rail near a sidebiter fin. The other is about 2 feet from the back of the board in between the deckpad break (where the stringer is). The pictures attached look like the one on the rail is worse but actually the one on the deck of the board is worse. the crack continues under the deck pad for just a bit.

My questions are as follows:

What could have caused them and is this normal for epoxy?

Would you suspect they are leaking and how could i fix them?

Someone suggesting clear finger nail polish as a way to fix small things like this.

Thanks for any help

Superglue,then coat the whole board in polyurethane.Herb

I wouldn’t even bother unless the foam is turning brown, leaking water.