3D Piping Workspace Issue
The basic install of Plant 3D 2021 did not seem to have the 3D Piping Workspace properly configured. As a result, selecting that workspace did not change the palette group leaving the P&ID palettes from the previous workspace active.
This is a simple fix.
Right clicking on any tool palette will display a dialog box that allows you to select Customize Palettes.
Select the Customize Palettes… option to open the Customize dialog for tool palettes and groups.
As you can see the specification palettes at the top of the left-hand column are not associated with the AutoCAD Plant 3D – Piping Components tool palette group.
Drag and drop the tool palettes from the column on the left to the tool palette group on the right as shown.
Click the Close button to exit the customize dialog box and save the changes. Now when you switch workspaces the 3D Piping workspace will display the correct tool palettes
Taking it a step further you save these changes and then import them to another Plant 3D installation. Open the AutoCAD Options dialog box and select the profiles tab. Clicking the Export… button on the right side of the dialog allows you to save the AutoCAD profile (options) settings to an external (.arg) file.
After exporting the corrected configuration, you can import it to other Plant 3D installations. Saving the configuration over the existing (you must type the name in) is the preferred method.