Are you trying to edit the endcap in place? That is working for me, in ACA 2022. The only way I could find that would interfere with that is if the current layer was turned off. Then I was only able to edit one component; the other components were not selectable. Having the current layer turned off is not a common thing (in my experience, anyway), so that may not be the issue you are experiencing.
If you can provide more details of your workflow (perhaps a Screencast?), that would help us understand what you are doing and may allow us to offer better suggestions.
David Koch
AutoCAD Architecture and Revit User
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