Seeing this increment specifically on the accounting table, while the authentication table's equivalent counter stays flat, would point the admin toward something wrong with the accounting server's response format or an intermediate device, such as a load balancer, mangling accounting-specific traffic on its own particular network path, distinct from whatever path authentication traffic takes. For example, this counter rising only after the accounting server was moved behind a new load balancer would point squarely at that load balancer's handling of RADIUS accounting UDP traffic.