Can someone spoil to me why ML told MC to quit his job? I do know spoilers about ML but I ...

In the previous life, Sejin's dad pinned the blame on Sejin for tax embezzlement in his company, resulting in Sejin being sent to prison. All the blame fell on him since he was the manager. That's why Ido is trying to prevent that from happening.

Did ML went back in time or both of them went back it time ??

Did ML went back in time or both of them went back it time ?? Or did MC lost his memories in same timeline ?

Both of them regressed, but only ML has all the memories.

Thanks