When a handle adornment is close to the edge of the screen, It will stop rendering, I don’t know the exact closeness it has to be but I captured this gif of the phenomenon
As you can see the red CubeHandleAdornment does not render when close to the screen edge, the white does this too when closer to the edge but the low frame rate of the gif does not adequately show this.
EDIT:
Here’s a Repro Place: NmTabs3.rbxl (12.1 KB)
It looks like it’s calculating whether it’s visible or not based on the centre position. That would explain why it disappears when it’s close to the edge.
It’s definitely not center position though, both are adorned to the same brick and the red one disappears when a corner is on the edge, If it was based on center then both would disappear at the same time.