The cause of this intermittent response for a small subset of stores was due to a bad/degraded AWS EC2 instance. On May 17th, 2021 at 2:30a EDT AWS informed us that they have detected degradation of the underlying hardware hosting our Amazon EC2 instance. Due to this degradation instance was rebooted twice in hope of recovery and urgent migration to a fresh node was initiated. Please feel free to contact MageMojo Support if you have any questions.