I have a Samsung Galaxy S9 with the software update to one UI 2.0 android 10. Developer settings are OFF and I do not intentionally destroy my phone. Anyways, I have factory reset my device 5 times deleting everything and manually reinstalling, automatically reinstalling, etc etc. I have powered my phone on and off 5 times, cleared hardware cache, opened safe mode, even accidentally opened developer mode and found YouTube solutions like an app called screen always on that I dismissed because ALL I WANT is to be ABLE to change the settings to whatever I want, whenever I want, however I want without the setting changing as soon as I turn my back on it. I change the setting called SCREEN TIMEOUT to 10 minutes because the moment I let my phone take 1 second to rest or relax without supervision it's like a toddler and changes back to 15 second timeout. I am NOT the only one with this problem. But I hope this is enough details for those who "can you give more info so I can help correctly" can help.
So if this problem is already solved do NOT give a link just give the solution COPY AND PASTE from that link if you're thinking about providing a website link whatever you want to call it.
Also if you agree or share this problem ONLY type AGREE and your phone specs. I don't need stories of your friends, families or adventures to wonderland. I need solutions not more problems.