How to Remove sticky adhesive from deck?

Try Goo Gone, works on most sticky stuff.

https://azek.com/resources/warranty-and-care/care-and-cleaning

I find that rubbing alcohol usually gets up sticky stuff.

spray with WD40 wait a few minutes and wipe off with soapy water. You may have to repeat.

I would go with WD40, with a little Dawn squirted on, also. Scrub with a scratchy sponge, then rinse with plain water. If the removal of the residue leaves a patch of the sealer removed or stained, you should patch the area with stain and sealer, since the deck is new. If you can’t, move the furniture around so a chair, table, or grill is over the area, or cover it with a cotton rug with no backing. That should buy you a couple of years until you resurface the deck. Best wishes ☺️