I see I should have read your original post more closely…”How do I know if I may be using too little pressure?” haha.

This is something I have no experience with so i really cannot comment.
All I can offer is that i once asked Greg about mp pressure in a Skype lesson and he said I only need enough to get a seal–again, my problem is too much pressure. Hopefully, Greg will chime in here.

Cheers,
Chris