I am having no problem.
Multiple elements on multiple layers on multiple storeys.
Using thick marquee I can drag all in plan and I can select and drag all in the 3D window as well.
Make sure you place the marquee and then invoke the drag command with the keyboard shortcut or even easier just make sure your marquee tool is still active.
If you don't you will only be selecting one element and that is the only one that will drag.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11