Hi! I'm not sure if this question has been discussed in another topic. Sorry if it's the case.
According to some web sites -for example, this one- the different plots of "Twin Peaks: The Return" are not happening at once. We just have to check the dates in the calendars or watches that they appear in the episodes.
The first picture below shows that the return of Cooper to our reality ocurrs at 2:53 of October (it's a still from Part 2). "2:53, October" are the indications that we can read in the note of the Mayor Briggs found by Bobby, Hawk and Truman into the chair. So, it means that the investigation of Bobby, Hawk and Truman is happening a few days before of the plot of Dougie.
It's a bit hard to explain, but I hope you can understand the point.
In the same vein, Andy would have appeared in two diffents timelines. One belongs to the investigation of Hawk, Truman following the instructions of Margaret -it happens in September as I explained in my first statement-. The other one corresponds to the moment when he's waiting for the owner of the truck previously driven by Richard Horne. As we can see in the picture below, the watch of Andy marks at that moment "October".
Ok. I've just discoreved another thread where everybody is discussing about this question. I keep the conversation there.