Dragon Rider 0.4.8
ElvUI 13.76

With ElvUI and Dragon Rider installed, my Vigor element shifts downwards every so often. I imagine this is because both addons are fighting for control of the element placement or that the Dragon Rider is adding itself as an element to the PowerBarWidget, causing the middle of the widget to be offset.

Normal:

https://i.imgur.com/GHAiiaL.png
https://i.imgur.com/XjUDg7h.png - ElvUI edit screen for reference, placement is where it should be

Shifted:

https://i.imgur.com/mdTQYt1.png
https://i.imgur.com/hWBfXN5.png - ElvUI edit screen for reference

Resolved for some time with a /reload, but happens again after a couple of minutes.

I'm frankly not sure what could be causing it. Dragon Rider doesn't mess with the positioning of the widget/encounter bar nor its container whatsoever, and since 0.4.5 it hasn't been Parented to any of those frames at all for it to try and adjust the boundaries of the widget child frame in the container. There seems like a good possibility there's something else involved in this.

Have you been able to discern a specific setting that modifies the positioning, such as if the vigor models are enabled, the static charge orbs are enabled, or speedometer positioning?

Something similar happens to me with GW2UI, but in my case DragonRider moves to the right.

With GW2UI I have the possibility to show or hide Blizzard's Vigor.

When I show Blizzard's Vigor, DragonRider is placed in the center of the screen and above the vigor. This would be correct.

But when I hide Blizzard's Vigor, DragonRider is placed offset to the right. Interestingly, if I do /reload while flying, DragonRider returns to its center position and stays in the center position as long as I stay on the mount, whether I'm flying or not. But if I dismount and remount, DragonRider moves back to the right.