OpenThread Border Router Issue

[Blackbox]

Good day. I'm having trouble regarding the OpenThread Border Router examples. I'm working with the "Wi-Fi based Thread Border Router" development board and using version 5.3.0 of the Espressif IDF.

I've tried following:
https://docs.espressif.com/projects/esp ... forms.html
https://github.com/espressif/esp-idf/tr ... read/ot_br
https://github.com/openthread/ot-docs/b ... f-esp32.md

I have loaded the "ot_br" example onto the ESP32-S3 and the "ot_rcp" example onto the ESP32-H2. When I monitor the ESP32-S3 Border Router, I get the following logs. Do you have any idea what could be causing the OPENTHREAD/Spinel issue?
I (538) main_task: Started on CPU0
I (548) main_task: Calling app_main()
I (558) uart: ESP_INTR_FLAG_IRAM flag not set while CONFIG_UART_ISR_IN_IRAM is enabled, flag updated
I (558) uart: ESP_INTR_FLAG_IRAM flag not set while CONFIG_UART_ISR_IN_IRAM is enabled, flag updated
I (568) OPENTHREAD: spinel UART interface initialization completed
I (558) main_task: Returned from app_main()
W(2588) OPENTHREAD:[W] P-SpinelDrive-: Wait for response timeout
W(4598) OPENTHREAD:[W] P-SpinelDrive-: Wait for response timeout
E(4598) OPENTHREAD:[C] P-SpinelDrive-: Failed to reset co-processor!
E(4598) OPENTHREAD:[C] Platform------: ResetCoprocessor() at spinel_driver.cpp:151: Failure

abort() was called at PC 0x4200842e on core 0
--- 0x4200842e: syscall_not_implemented_aborts at C:/Users/.../esp/v5.3/esp-idf/components/newlib/syscalls.c:27

[tim.jrz]

I also have this problem and i haven't gotten ANY combination of chips to work. I tried a C3 with a C6 in all sorts of configurations, nothing.
I bought an ESP Thread Border Router Board with an S3 and an H2 and still nothing works. It worked on the factory hardware though...

I followed the guide on https://docs.espressif.com/projects/esp ... d_run.html step by step. How is there not any real documentation on this problem??