Here, we describe a case of α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor (AMPA‐R) and collapsin response mediator protein 5 (CRMP‐5) antibody‐positive autoimmune encephalitis that developed in a patient with acetylcholine receptor (AChR)‐positive MG with a known thymoma in the setting of COVID‐19. This evidence concerns the gene DPYSL5 and thymoma.