No padlock shows except on login page

I have selected secure posts for my page pepperpotcottage.co.uk/card-payment but whilst https comes up the padlock only briefly shows before disappearing.

However both https and the padlock show when I am on my admin login page ( I have selected Always use HTTPS while in the admin panel).

How do I make the padlock show permanently on my pepperpotcottage.co.uk/card-payment page?