Dual core H7 debugging problem in CubeIDE

I have a problem with launching both cores in STM32H745 in CubeIDE.

I've set that configuration:

• connect under reset for CM7, with halt all cores
• Cross Trigger Interface (CTI) , allow other cores to halt this core and signal halts events to other cores for both core 4 and 7
• different port numbers for first and second core
• in CM7 startup I added file *.elf from CM4 with option to download CM4 core
• in CM4 startup I don't allow it to download this core
• I set launch group which starts both cores

After starting I see that the LED on CM4 turn on only for a very short moment and then turn on only LED on CM7.

Therefore, I can debug only with BOOT0 connected to 3V3. If it's not connected it's impossible to connect with ST-Link. I guess that it's not right but I really don't know what cause this problem. Maybe it also cause that core CM4 finishes working.

Can you help me or give any link which could help me to configure debugger in CubeIDE or tell why I have a problem with connection without BOOT0?