Hi Kevin,
the problem is created by your app task
xTaskCreate(app, "App", 1024 * 20, NULL, uart_task_PRIORITY, NULL);
Above you are creating that task with 80 kByte (!!!) stack. This causes problem in the task view (of course it should not create that issue, so I have reported it to the developer).
If you use 4K (1024) instead of 80KByte, the problem goes away.
Can you give this a try?
Thanks,
Erich