You should give your employer a Maryland Form MW507 so they will not withhold Maryland state taxes - https://www.marylandtaxes.gov/forms/current_forms/mw507.pdf
The employer should only withhold Virginia state taxes from your wages.
TurboTax support FAQ - https://ttlc.intuit.com/turbotax-support/en-us/help-article/state-taxes/states-reciprocal-agreements...
