esp32-wifi | Rust ESP32 WiFi Library | Wifi library

You may have two tasks and two cores, but the ESP32 still has only one wifi chip. The way your code is written (at least, the code you shared), you'll be trying to connect to a wifi network at the same time as you're trying to run promiscuous mode. You can do only one of those things at a time.

You'll need to stop promiscuous mode before you attempt to connect to an access point. Right now your code constantly attempt to connect to a wifi access point. Use a volatile variable to store the current mode - promiscuous or connected. Change it when you need to change states. Only attempt to connect to wifi when the variable says you want to be in connected mode.

There may be some code you need to run to turn off promiscuous mode when you change states, before you connect to a wifi access point.

If you're using wifi_sniffer_init() from the example you linked to, that code isn't meant to be run in an Arduino Core application. It does some network initialization that the Arduino Core will also do. It may not be safe to do that twice (it might work, it might not... but it's definitely not intended to be done that way).

You're setting an interrupt handle chUpdate() which you didn't share. I'd bet that's the cause of your Core Panics. You can do very little in an interrupt handler. You definitely can't call most Arduino Core functions or most ESP-IDF functions. Most code isn't protected against interrupts, so the timer interrupt can occur while data structures are in an inconsistent state. Re-entering code can corrupt the data structures and cause the kind of crash you described. You're best off setting a volatile variable and waking up a task that will do the work you need done while not in the interrupt handler.

Finally, you should call WiFi.mode(WIFI_STA); before you call WiFi.begin().

For anyone confused about why you can't connect to a wifi network while in promiscuous mode - what ESP8266 and ESP32 call "promiscuous mode" is really "wifi monitor mode", which lets you monitor a wifi radio channel and see all wifi frames sent on it. They use the term "promiscuous mode" differently from the rest of the industry. Usually "promiscuous mode" means seeing all the packets being sent on the network (wifi or hardwired) that you're connected to.