CPU blocked during the WIFI connection process to router

[feng0020]

I am working on a project that ESP32 playing the MIDI files stored in the internal flash (ESP32-WROOM-32E).
However I have noticed that whenever my device is connecting to a router, the music paused a bit (jitter in music). I have ensured that all the task is assigned to core 1 instead of core 0, which wifi task is assigned to core 0 in menuconfig.

I suspect that it is due to "Concurrency Constraints for flash on SPI1" (https://docs.espressif.com/projects/esp ... rency.html). However I have disabled the NVS option of WIFI in menuconfig, and the problem still persist.

My question is that is WiFi write access flash during the connection process that causing the issue? How I can improve on this jitter. Or is anything I missed that it caused by other reasons? Please give me some hint and I will do further exploration.