I buy good bras and have them fitted from Bravissimo. They fit nicely and look good... but within hours of wearing them they slip off my shoulders. It’s so annoying! I am larger and have 36GG/H . I like Fantasie bras as they don’t come up so high under my armpits ( another problem) and they are brilliant apart from slipping off my shoulders! That’s even with straps tight and correct. I have had other makes too such as bravissimo own etc. I must have narrow shoulders! Can anyone offer suggestions please?