iPhone 16 running iOS 18.5 StandBy mode shuts off screen after a few hours

I disagree. We’ve two 16’s, purchased at the same time. Settings identical. They both have sleep ficus on. One phone works perfectly on standby and the other blacks out about every four hours. Only difference is the brand of case and we swapped that last night, same problem same phone. As for the other critical settings, they are correct, ie. low power off, always on etc. I believe this is an ongoing software issue as I can find threads on this going back a few years. It needs to be addressed. What I can’t understand though is why only at night and not every phone. By the way, phones were purchased at Verizon, her phone was returned 4 days later and exchanged but the new(er) phone has the same issue… and it would because it’s set up using the latest backup. So the problem travels through the backup. I believe that it’s some combination of things that she has, which I don’t (even though all settings are identical… we did that three days ago).

so right now we have to live with it.