Thanks again for the suggestions. A number of States including California and Louisiana tax non-residents if they receive income from an employer registered in the State. We moved from Louisiana to Texas in 2010 and have never been back but have paid Louisiana State taxes on my W2 income (a non-qualified pension) from my ex-employer ever since.
We moved to England in 2016 but the USA is the only country in the world, apart from Eritrea, to tax its citizens on their worldwide income regardless of where they live. It is what it is.
I tried Googling what would happen if I e-filed my federal return twice and I believe it will simply be rejected, no penalty or anything so I think I will try e-filing both returns together like TurboTax prefers and see if that works.
