I am on an IPhone 13 Pro Max.
Went over my post again and wanted to make a couple clarifications:
I don’t logout after a short time if the runescape app is open, only if I minimize it. This has always been the case but is only now an issue because of the lengthy login process.
Also, very infrequently, it lets me log in with one click like it used to. There doesn’t seem to be any rhyme or reason as to when it does vs. when it doesn’t but it’s definitely about 90% of the time that I have to login manually. If I get a connection error and get booted to the login, which happens a lot playing on mobile w/ data, I 100% have to login manually again.
I thought this was an issue with Jagex Accounts, but other redditors are having conflicting scenarios occur, so it’s probably a mobile bug.