To start with, even if you would be entitled to a refund, it is too late to claim one. There is a three-year limitation on claiming a refund with an amended tax return from the filing date including valid extensions. Assuming you filed your 2017 Virginia return on time, April 15, 2018, then the deadline to claim a refund was April 15, 2021.
Regarding your timeline, you have not discussed the location of your domicile. Your domicile is your permanent home, and you can only have one domicile at a time. There is no single factor that determines the location of your domicile, but important factors include whether you own or lease a home, where your car is registered, where you are registered to vote, the location of your doctor, dentist, attorney, and the location of your significant social relationships. You can only have one domicile at a time and in order to establish a new domicile you must also take active steps to abandon your prior domicile. It is possible to live away from your domicile for many years without actually changing your domicile.
If you are domiciled in Virginia, then you are required to file a Virginia tax return as a resident, and report and pay income tax on all your worldwide income, regardless of where you were living or working when you earned the income.
If you are not domiciled in Virginia, then you would only be required to file a Virginia non-resident tax return to report and pay income tax on any Virginia-sourced income, that is income that was paid to you while you were physically living or working in the state of Virginia, or income from Virginia sources like the lottery or sale of property. Working for a company based in Virginia is not by itself considered Virginia-sourced income if you were domiciled outside the state and physically living and working out of the state.
