Use the Guam CNMI visa waiver to travel to Guam. This is not esta. Do not tell the airline you are an LPR.
At the port of entry identify yourself as an LPR. Prepare to pay the I-193 fee. Refuse to sign I-407. Ask for an I-551 stamp at port of entry.
Otherwise, once admitted to the USA, call USCIS, say “info pass”, and request an appointment to get an I-551 stamp. Do not leave the U.S. until you have a stamp. Next time come back to the U.S. before your I-551 expires.