Air force 2 plane changes call sign to Anon

This is a known Air force 2 plane registration number 98-0002. I tracked this plane out of DC and it landed at Phoenix Sky harbor. It then changes its call sign to "Anon." HIGHLY unusual! Upon take off it changed back to SAM743. Back on Feb 9, 2021 I took screenshots of a plane out of Savannah, GA with the letter "Q" added to it's normal call sign. This plane flew from Savannah, GA to Tercierra island. Then upon takeoff dropped the "Q" then. That's 2 Q planes in 10 days. Do you believe in coincidences?