Hello!
Interesting! I am pretty sure I know what the problem is. Let me ask you for some details to confirm.
Please detail for me your grip for Half Moon (and other similar grip poses). Put yourself into the pose now and tell me if your focus is more on your palms and fingers together, or your thumbs crossed? What are you aiming for in your grip and what exact instructions are you trying to embody?
And please describe how you hold your hands in Standing Head to Knee, and Floor Head to Knee. To what extent do you make sure your thumbs are crossed in the grip of these poses?
Namaste
Gabrielle 🙂