There could be a few solutions to your problem.
If you are not seeing any white solid fills at all then it could be your Graphics Overrides.
Try choosing a different one or there should be one that says "No Overrides".
Or it could be transparency has been set in Trace & Reference - but lets try the GO first.
If your plumbing fixtures do have a white fill then it could be display order - but fills will go behind objects by default so I doubt this is the problem.
You can select elements and adjust the display order forwards or backwards in relation to other elements - it will not affect there 3D position.
Barry.
One of the forum moderators.
Versions 6.5 to 25
Dell XPS- i7-6700 @ 3.4Ghz, 16GB ram, GeForce GTX 960 (2GB), Windows 10
Dell Precision 3510 - i7 6820HQ @ 2.70GHz, 16GB RAM, AMD FirePro W5130M, Windows 10