Hello Mom,
Today USCIS updated my son's case as:
Post Office returned a notice we sent you for your Form I-485, Application to Register Permanent Residence or Adjust Status, Receipt Number xxxxx, because they could not deliver it. This could have a serious effect on your case. Please go to www.uscis.gov/e-request to request a copy of the notice immediately.
I have already requested the NOA using the online tool. Should I call them and explain the situation or wait for their online response?
By the way, I checked our current address was accurately written on my son's I-485.
Thank you,