Soft SUP bubble trouble

I have a soft SUP a couple of years old which has developed some big air bubbles on the deck (around 20cm across) - granted it has been permanently stored in the sun which obviously isn't a great idea, a 40+ degree day last week was the last straw... I've seen the same thing on cheap kids body boards, I guess some kind of delamination / glue giving up type thing?

Anyway, its not an expensive board but worth having around for kids / people beginning etc so I'd like to salvage it. Don't know much about this kind of thing but thinking it might work to cut open the bubbles and re-glue that layer down? Not sure what with? Its also not a very grippy deck so thought after sticking bubbles back down might work to then put some kind of deck grip pad over the whole thing. Any suggestions? (Apart from the obvious don't store boards out in the sun / don't buy cheap boards in the first place!)

I would recommend the new class of glues: the "MS polymer" ones (MS for Modified Silane). They are incredibly strong, but leave you some time to reposition (depending on the brand), are solvent-less (do not damage the board if you want to remove it), and use air moisture as a hardener (thus some humidity is no issue). They take some hours to get full strength (depends on the brand). Also they stay supple, which is great for use with pads.

See www.adhesiveandglue.com/modified-silane.html

I use the "UHU max repair", as it is one of the stronger in tests, and hardens fast, but other ones are listed at the end of www.gong-galaxy.com/forum/viewtopic.php?f=62&t=7686&start=30 (the list after "Pattex Heimwerker"