I've had a similar problem in the past going between different PC's. It was caused by the installation of the same plugins( from the same installation files) beings slightly different between my PCs. It took me a while to figure out and was pretty frustrating. Is there anything added behind the name of the plugin '64bit' or anything like that because Studio One will see it as an entirely different effect? So I would look for that as that's what my problem was. In my case I had to install the VST's twice in order to get 64bit behind the name to avoid redoing them. I have since changed the installation on the first machine, removed the second instance of the plugins on the second PC and everything is good.
I loaded up your template. While I don't have Auto Key, Auto Tune EX, Auto Tune Pro, H Delay, S1 Imager(s)[ But I have S1 Imager Stereo, is it the same? Seems likely], or Doubler2(m<s) [but I've got Doubler2 Mono / Stereo, I don't know if that's the same plugin, pretty likely]. Everything else loads fine. RDesser Mono, RCompressor Mono, REQ6 Mono, RVox Mono, C4 Mono, S1StereoImager Mono,ect. They all work great. So it looks like it might be a naming issue with '(s)' as opposed Stereo on my machine. But then again it might not be the case on your machine. But it leaves me thinking, how do you rename plugins or create plugin aliases in Studio One? I'm not sure. But I'm feeling like if it's possible to rename them, you might have this fixed pretty easy. If not you may have to find a round about way to do it, multiple installs, registry tweak, I'm just not sure how. Anyway, that's my best guess.
My only other guess at this point, does the Mac have a 32bit bridge built in, I don't own a Mac, or are you running one? If that's the case the effects your using wouldn't be available since Windows/ Studio One doesn't have a bit bridge. So it would be using 32bit effects as opposed to 64. I'm thinking this is pretty unlikely but I haven't seen '(s)' behind the plugin name in many years, but it was very common on my 32bit VST's.
Lastly, if a plugin shows up on one track, every instance is activated on all tracks. So I have no problem there.
Good luck.