The following notice appears on NARA’s website:

Due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of our staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgment as well as a substantive response to your reference or FOIA request or appeal. We apologize for this inconvenience and appreciate your understanding and patience.

Read more here.