Discussing the different theories of how, when and what was going on with the timeline, existence of dimensions within this drama.

My take on it is that there are multiple time jumps within 2 different timeline. 

The sequel will likely take place on the alternate timeline because it's said that Zhang Wensen goes back in time. Knowing the prequel, it's impossible for Zhang Wensen to have traveled back in time from the previous timeline. It wouldn't work because then the prequel story wouldn't have worked out. 

I believe Zhang Wensen might be able to merge the two different time lines (if it's a happy ending).

If not, one of them will stay in the other's original time line.