The Duplicate Test modal defaults to duplicating tests as a "Simple Personalisation" regardless of what type of test the original was. So, for example, if I am duplicating an A/B Test, the modal will duplicate it as a "Simple Personalisation" unless I otherwise specify.
If I am paying attention I will specify the correct form in which the test should be duplicated. However, I often forget and then am left wondering where my duplicate test is!
I think it would be better if the duplicate modal defaulted to the original type of test, which could then be changed as needed.