It took forever for it to get back to normal here. There was limited TP available after the initial panic, but it took months to get anything decent on the shelves. I was ordering it online for a while.
With the world shutting down the companies that supply those kinds of places had a warehouse full of inventory and most of their usual customers either were entirely shut or going through a lot less product.
I'll wager your grocery store called one of them up and got a few pallets to resell, creative move on their part.