Thank you Ellen and Roger. Any help you can give to resolve this problem is very much appreciated.
I have given up trying to use them, but I own 3 Starboards and I have had to replace all the straps,
at considerable expense, with DaKine Contour straps. This is just to be able to use my boards without having to mess with the Starboard straps each and every sailing session.
To repeat - Starboard should supply straps fit for their purpose.