I, as well as other online users, are having this issue. I opened a ticket for this issue but there doesnt seem to be a solution. Here is what I wrote in my ticket....
"Hi. Im having a major issue. Studio One seems to do a great job at being customizable to all users. However, there is one thing that is hindering my workflow in a terrible way. Now, in MY mind, I think it makes more sense to have the BUS for a cluster of tracks on the LEFT. Yes, yes, I know there is the option "Keep Bus channels to the right." Ive explored this many times. Heres the issue. I create a set of tracks, such as drum tracks. I will then create a bus for those tracks. That bus pops up on the RIGHT side of those tracks. I want the BUS to be on the LEFT. So I will move the bus to the left of those tracks manually. But once I add another track, say like a piano track, it may pop up in the middle of the drum tracks. This seems to be a bug. Once I am deep into a session, with many tracks and busses, each time I open my session, tracks are scattered everywhere in the wrong places. (I asked others on the presonus page on facebook and they were seeing the same issue. I know there are unorthodox ways to rig this and that, possibly using folders etc.... But again, Studio One was AND should be designed for quicker workflow. In my mind, busses should be to the left of a cluster of tracks that they are bussed to. I have done a ton of research on this and there doesnt seem to be a solution."
I was, of course, told about the option to uncheck the boxes for keeping the bus on the right... But the issue is, tracks are randomly scattered throughout. Guitar tracks will be wedged in the middle of vocal tracks... The Strings bus will have moved farrrr away from where I had it and end up beside another bus which is ALSO in the wrong place. Seems to get worse when shutting down the session and re-opening it. This is true with FX busses as well...