Why NASA Immediately Suspended All Mars Missions

On November 11, NASA stopped sending commands to Martian spacecraft, and this communication blackout will continue until November 25.
The reason for this two-week hiatus is because Mars is currently in solar conjunction, meaning the Sun currently lies directly between Earth and Mars, and radio commands could be disrupted by the Sun's charged particles.
Although receiving no new commands, the Martian rovers, satellites, and one tiny helicopter will have a pre-planned list of scientific objectives and will continue to send health checks during the two-week break.