If you moved to WV in 2019, your employer should not have withheld ANY MD taxes for 2020.
If you haven't already done so, submit MD Form MW507 (as @Mike9241 stated) to your MD employer ASAP, checking the West Virginia box on Line 4.
For your 2020 tax returns, enter your W-2 exactly as is.
For 2020, file a non-resident 2020 tax return to MD, showing zero MD income. This will cause MD to refund the incorrectly withheld MD taxes.
File a 2020 resident tax return to WV. All your 2020 income is taxable by your 2020 home state of WV.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
