Note I had a minor usps scare. Usps mis delivered package on June 28th Thursday. I waited for day in case it shows up (in hindsight should have immediately gone next day). I went in usps on july3rd Monday and also tmed to mail main and attempted to track this down. Luckily as of today gc is delivered.
Note never had issues of package mis delivery but one idea could be to pick up green card directly at post office if possible. Also subscribe to usps mail delivery to know what packages are incoming that day.