As I was playing as John Marston the "I Know You" stranger quest never appeared on my map, ever! Now that I'm checking all the things I've done whilst playing as Jack Marston with multiple saves overwriting my previous game saves, I've realised that there's no way to do that mission.

I know it's not a necessary requirement for the 100% completion but is there any possible way, maybe by cheats or anything in order to change my character back to John Marston for that stranger question to appear again?

Please help.