Custom external flash loader operations fail after erasing internal flash sector

[ATrec.1]

I've created a project for W25Q32BV QSPI flash on STM32H743B microcontroller (custom board), following explanations in https://www.youtube.com/playlist?list=PLnMKNibPkDnHIrq5BICcFhLsmJFI_ytvE.

The loader also print some execution information over UART so I'm able to trace "what loader is doing" (see terminal windows in attached video).

I've loaded the generated .stldr file on STM32CubeProgrammer and everithing works right (read, erase, write) until I made operation in external memory only, but if I "mix" some operation in internal flash, my loader stops working, apparently the Init function of loader is no more executed.

Any idea of how can internal flash operations "disturb" my code execution? Thanks in advance.

[ATrec.1]

Nobody can help me? Is very hard for me understand what happer whith STM32Programmer, how it uses loaders: I supposed that each time is needed to access internal/external flash, the appropriate loader is written in RAM, but, in this case how is possible that external flash loader don't work properly after using internal flash loader? I can share my code if someone could help. Thanks.