tbn, I also don't really like that idea ("we were lovers in a past life so you're going to be my lover in this life too") but I'm pretty sure that Ian is reincarnated, which means he is the same person but in a different body - without his memories ofc - ( i think at least) so once he recovers his memories he'll probably revert to what he was like or whatever and then Sol and Ian are probably going to be a normal relationship without it feeling rlly forced.
sorry I feel like I had to dump down what I was thinking 🙃