Ahh, yes, you are correct.  In all my Androids, I have an app called Ultimate Rotation Control that I usually have set to forced rotate.  Setting to auto does as you say.

I didn't clue into that background app affecting RemoteXY as I also saw the same result on an iPad... which doesn't have such a 3rd party app running.

And it was in iOS that I found the "issue" most disconcerting as it just keeps on saying "Connecting" if held, or later turned, in the incorrect orientation of the app project.

Perhaps forced rotation is a built-in "feature" in iOS   I rarely use Apple stuff so don't know.

Only to realize that I am inevitably holding the phone in the wrong orientation for the elements to display (I constantly adjust the App layout according to personal preferences for the project).

In android, this results in blank App screen, in iOS is seems to keep displaying it's connecting circle.

Perhaps a slight adjustment to the App that forces it to display something regardless of orientation (force rotation of display), or at least display a message stating something like "Rotate the darn phone you doofus "