Refer to the above - USCIS acknowledged the delays and looks like ETA is 30 days - you can drop an email to
lockboxsupport@uscis.dhs.gov
below is the standard response that I received -
Thank you for contacting Lockbox Support.
If your inquiry is not related to a form received at the lockbox, is not a general question related to the lockbox or has been forwarded to a USCIS Center for further processing, you will not receive a response beyond this reply.
Inquiries related to a form received at the lockbox or general questions related to the lockbox, should receive a response within 30 business days, with the following exception:
An inquiry related to a receipt notice for Form I-751, Petition to Remove Conditions on Residence or I-829, Petition by Investor to Remove Conditions on Permanent Resident Status will not be addressed, as those notices are not printed by the lockbox.
The Lockbox has recently experienced a significant increase in filings. This, in addition to the restrictions put in place because of the COVID-19 pandemic is causing significant delays for processing receipt notices. USCIS continues to work hard to minimize delays.
Duplicate requests for status and updates will not receive a response.
For additional information and guidance, visit our USCIS website. Our website provides current forms, filing instructions and fee guidance at no charge.
For inquiries unrelated to lockbox processing, please refer to the guidance on the USCIS Contact Center and USCIS Tools web pages to request assistance.
The Lockbox Support Team
U.S. Citizenship and Immigration Services