I am intrigued by the need for the tests when your consultant was confident that you are Type 1.
As
@Fenn said, if you have Type 1 as an adult, your body can take some time to kill off all your beta cells producing insulin, As my injected insulin dose continued to rise for 8 years after I was first diagnosed, I suspect I was still producing a low level of insulin until that point.
If the nurse says you are producing less insulin than normal and you still need insulin, I think the important thing is to ensure you are recorded as having Type 1 (sadly, some treatment options are not available to people with type 2) and focus on understanding how your insulin works for you and making the most of it.