@N-Steven3
I changed out the door knob to one that doesn't have a lock. HD and Loews carries them. Entrance door knob with no lock.
If not guest will lock it while inside, say before the go to bed, as extra lock, then exit the house forgetting to unlock it. It's a safety feature with all of them, where you don't have to unlock to exit, but then door is locked when closed, so guest would be locked out.
Here is one. I use a stainless steel one.
https://www.lowes.com/pd/Schlage-Bowery-Knob-with-Addison-Trim-Hall-and-Closet-Lock-in-Matte-Black/5...