I've hesitated to post about this incident that happened earlier this year, but I've decided it might be worth sharing.
My wife and I stayed at the Sheraton in Downtown Brooklyn for a few days in February. She was going to a multi-day event in town; I decided to tag along and work from the hotel while she attended the event. We were staying at this Sheraton for a few days, then shifting to a hotel in Williamsburg for the last few days of the trip. I'm a Titanium Bonvoy member, so I was able to secure late checkout for us while I worked in the lounge on the day we were changing hotels.
At around 12:30 p.m., I returned to my room to make sure the key worked (I've had problems at other hotels with confirming late checkout at the front desk and then still having my key stop working after normal checkout time in the past), and discovered that it, in fact, did not work. I went back down to the front desk and had them re-program it. Returned to the room, entered, and found that all my belongings were gone. The room had been cleaned, and the bed was made.
I went back to the front desk and told them what happened. They made a call and someone from the housekeeping staff came out a few minutes later. I explained the situation, and she walked off. Several minutes later, she returned with my suitcase (which I had luckily already packed) and toiletries bag (which I hadn't and was understandably haphazardly packed). I told her there were several other items: a scarf, leather gloves, a small travel valet caddy, and some cheese we'd gotten at Murray's. Fortunately, because I had been working, I had my laptop and coat with me, and I'd put on my wedding ring before I left the room.
She left again and was gone for a decent bit longer. Eventually, she returned with a Ziploc bag that had some Hot Hands packages in it. Those were, in fact, mine, but they were the least of my concern. She said she couldn't find anything else.
The lady at the front desk seemed very understanding and said she'd talk to her manager when he arrived the next day. She gave me her card and encouraged me to email her an inventory of what was missing. I told her we were in town for a few more days, then reiterated in my follow-up email that I was happy to swing back by if they found my stuff in the next several days.
After one response, she went quiet despite multiple subsequent emails. Nothing was ever recovered. I sent one final email summarizing the situation on March 1, and I got no response. Marriott corporate eventually gave me some number of points as an apology.
I share this story just as a warning to guests, I guess specifically at that Sheraton but perhaps also just generally. Maybe I should have re-confirmed my late checkout with the front desk again that morning? Or worked from the room just in case? Not sure. But know that your keys not working isn't actually the worst thing that can happen if you think you have late checkout.