3D text is a 3D object and you can not copy and paste any 3D elements in the 3D or elevation/section window.
You either need to copy and paste in the plan window or in 3D (section/elevation) you can drag a copy.
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