Don’t use the void loop() for running stuff if you have two seperate threads already for your stuff. Put Blynk.run in one thread and do all other in the other one.
I’ve also noticed a tendency in the ESp32 that it needs a certain delay in the created loops. Try adding vTaskDelay(10); in your vTask loops.
There is an example of how I did here: Three LEDs with Dirty Delay (ESP32)
Hope it helps 
-edit-
vTaskDelay(500) looks a bit too much, change that to 1 and see what happens. Just let that task run with the Blynk.run() in it