Coupons aren’t being applied to our user role ‘Wholesale Customer’. The coupon is set to all roles and gets applied to normal customers but the Wholesale Customers doesn’t get the coupons (it is being auto applied). I can even make a new coupon with should be applied just to a test wholesale user with no user restrictions and that isn’t applied. The test user is a completely new user and only has the Wholesale Customer role.
Your suggestions has led to the discovery that the coupon field is just missing for the wholesale role users. So the issue seems to be something to do with our wholesale plugin and we are looking into that now – thanks for the response.