I don’t think it’s just memory management at play. I’m having the same issue on iOS on an iPhone 11 Pro. Yesterday I was writing a comment, swapped to my browser, did a quick search, and came back within 30 seconds… and found myself staring at my home feed instead of the comment I was drafting.
Of course, it could still be memory management related, but I don’t tend to find other apps getting reloaded even after much more time away and switching between more than one other app.
Additionally, shouldn’t the app remember your position regardless? It’s annoying to lose my place in the feed and find myself transported to the top of the Home feed. Maybe not and that behavior all falls under memory management… I’m not a programmer.