Most hotels right now are not offering housekeeping while staying there. They don’t come to clean til after you check out.
This is an excellent point with COVID.
My experience with the industry is now dated, but I worked in housekeeping as well as the front desk along with auditing, and the Do Not Disturb sign meant exactly that. Plus, housekeepers usually did not have access to who was staying for how long, communications between the front desk and housekeeping wasn't always up to snuff, and unwanted disturbances could result in a free comp/gratis compensation for the guest.
Regardless, they work for YOU, so you do not owe them any explanation. I audited for Motel 6 and in the early internet era, M6 was a popular chain for producing porn (which everybody who stayed or worked at Motel 6 knew because of their distinctive corporate standard bedquilts), and hotel and motel rooms are still the usual venue for producing smut images and clips. Anyhow, most housekeepers are not interesting in interrupting, seeing or walking in on something like that.
Arranging for a ground floor room might be a good idea, since if something goes wrong, you won't risk disturbing somebody in a room beneath you.
Neither I or any staffers I worked with ever called anybody on grounds of any kind of suspicion. These businesses are looking to make money and survive by renting rooms, particularly during quieter times of the week and year, so stay away from holidays and weekends. (People only got turned away if they had a bad previous history with the establishments I worked for.)
Suicides took place at every single establishment I ever worked at, although incredibly, nobody died at any of those places when I worked at them.
You can call ahead without identifying yourself to try finding out when business is slowest and rooms are least expensive.