Your items are not being shown in search by eBay, but they may still show up in google searches, and an eBay buyer who has put one of your items into their watchlist can still see it there.
I found some of your listings in google searches, but when I open a listing, I can't do buy now, or send an offer. I can put it in my watchlist, or in my cart, but once it is in my cart, I can't pay for it. There's a red banner that says:
"The seller's store is closed for vacation. Check back later."
In my watchlist, there is a "Make offer" button, but when I click it, it just opens the listing and there's no way to make an offer from the listing.
So, I can confirm that you did set your time away settings correctly, and as far as I can see, buyers can't purchase or make an offer on your listings.
The only thing I can think of, is maybe your potential buyer sent the offer just before you put your listings on time away, or maybe they had already started the process, and completed sending the offer sometime after you went on time away.
If you accept the offer now, you will be expected to ship the item within your set handling time. If you don't, then you would get a late shipping mark on your account. If it's a good sale, and the buyer is willing to wait, then it might be worth it. Otherwise you could reply that you are unable to ship right now, so you have to decline the offer, but that you would be willing to accept the offer if they can wait and send it again when your store is open again.
