回複：Help with address change

1) possible, I changed my address by file ar11 and i485 on line but still lost uscis mails. When the mail returned to uscis, they resent to my new address which i never told them.

2) You must file ar11 by law.one lawyer said it won't be problem before uscis knew. I asked an imm. officer, if i stayed somewhere less than six months, did i need change my address? the answer is 'no'.