The Downside of 3 Monitors
Okay, so having 3 monitors is always a good thing, right? Lots of room to work, you can break your apps into separate windows and move them across monitors, etc. No way there's a downside to that, right?
Well....
So I'm using D|S, and I want to apply a pose preset to a character. Select the character, click on the pose preset icon, and you're done, right?
Well...
I kept waiting and waiting for the pose to be applied. And waiting. And it was like D|S was locked up. I couldn't do or select anything. So I shut it down with Task Manager, restart D|S, and try again, this time with a different pose preset.
Same thing happened...
HUH??
So I'm scratching my head, and out of the corner of my eye while I'm looking at my HWMonitor to see if D|S is still using the CPU, I notice a window up in the top right corner of my RH monitor.
"Pose is outside limits..."
DOH !!! It was waiting for me to respond all this time.
So, DAZ, please, is there some way to force notifications to the primary (center) monitor for us dumb folks? Please?

Comments
Is your center monitor actually configured as the primary monitor? It almost sounds like Windows is treating the right hand monitor as the primary one to me.
yeah my left hand has to be my BIOS monitor as its the only one that will see it, so lots of things from DAZ studio and other programs pop up there, windows itself opens on the centre one, and D|S is actually spread between my middle and right ones.
No real solution in my case due to the type of outputs available on my 980ti and what each monitor can use.
I want the 27" in the middle and the 2x23" angled either side as it just looks wrong otherwise.
Yeah, the center monitor is primary, but I think I confused D|S by moving the render status window over there or something.
Using DS if I place the main program on my main monitor and a DS Aux Viewport window on my secondary monitor then the menus all shift off screen from my main monitor.
I no longer remember the details, however a very long time ago I vaguely recall seeing an option that allowed me to move pop-up dialogs to one monitor, as the default with a 2-monitor setup was to put it right in the middle of the windows desktop (half on one monitor and half on the other, very hard to read.) I'm thinking that might have been a setting somewhere in the Nvidia settings for the graphics card? But I'm not sure. Might be worth looking into.
One thing to remember is that the ports on the back of the video card are numbered so to speak, just a matter of finding which output on the card is the main output and then plug your main monitor into it..
DVI is often the primary one, but not all cards have one; seem to recall there are 1080ti without it.
That might be it; I always used to have all my status popups in the middle of my (only) monitor, until one day I moved the render status off to the side so I could see what was happening underneath. Ever since then, all my popups have appeared off to the side.
I move the render windows on a regular basis (and use 3 monitors), and Daz is never as confused as I am; all joking aside, I've not noticed the issue you're having.