Trying to drop off a package at a desk that kept migrating

So I was at one of those little shipping offices, the kind with the drop-off counter and the clerk behind a glass partition. I had this medium cardboard box, shoebox size, tape on the edges. I set it down and the guy was peeling adhesive labels off one clipboard and slapping them onto another. I said ‘hey, I need to ship this out’ and my voice just bonked. Like a muffled thump against the glass. He kept rearranging. Then I looked up and the whole counter section had slid maybe six feet down the wall, and now the register was behind me. The box in my hands felt heavier, like somebody swapped the contents for something denser while I was talking. I kept walking toward the counter trying to get it back to the right spot but every time I got within a few feet the glass shifted. Like a bad game of musical chairs with furniture. Ended up just setting the box on the tile floor, peeling my shoes off because my feet were soaked for no reason, and walking out. The parking lot was full of kick scooters. None of them with a rider. Just parked in neat little rows. Felt weirdly satisfied, like I had finally dropped the thing off, even though I clearly hadn’t.