System Workbench for STM32

Hi there! I need someone's advise...
Processor - STM32H745
Board - DISCO
SW4STM
The situation in my project is the same as described in the first post of this thread. By the way i have created huge code for CM7 core under FREERTOS, and there were no problem, but when I started to investigate CM4 I meet this strange behaviour.
The first task for me is to make inter-core communication channel, I tried to use examples from cube, especially OpenAMP library. So it works well until I have enabled FREERTOS on CM4. OpenAMP Example code became unworkable. Trying to debug it i've noticed that problem appears after starting scheduler. Using any breakpoint, after it starts, hangs debugger for CM4. The picture is the same as in the first post. Nevertheless, i tried to use code from the example provided by the cube for inter-core AMP "FreeRTOS_AMP_Dual_RTOS". So debug works, until I tried to delete some code for migrating to OpenAMP.
For examle : CM4\main.c
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin){
prvCore2InterruptHandler(); If I comment this line debugger hangs in freertos task
HAL_EXTI_D2_ClearFlag(EXTI_LINE0);
}
I'm sure that my interrupts are switched off, so this routine never used... I'm lost...
By the way, when I was debugging CM7 there was a similar problem when I was debugging Huge ISR routine (the processing should be fast), so there were some hangs of debugger described in post 1, but I've debugged it through console messages through RS232. So in CM7 this bug was only in debugger, but not in code...
May be someone can show me direction for digging...
Thank you for your patience!