Mesa 5i25 config for chinese BOB

I flashed the 6i25 with the 5i25_5ABOBx2.bit. Now when I turn on the PC the red led flashes 1 time and the PC turn off for 3-4 seconds, then my PC turns on by itself and mesa card flash 1 time again, after booting I realize that the file is been replaced again for the previous one (I lose my pin pwm)

Are you using Pathpilot? nothing can change the loaded firmware unless its a startup script like pathpilot uses if it does not like the loaded firmware...

I'm using LinuxCNC (axis gui), "linuxcnc-stretch-uspace-amd64-r10.iso ".I tried in both ways to reload the card, with the command --reload and completely turn off the PC and turn on it again, but in the end my firmware is always replaced. I'm going to try with another pc now.

Your firmware cannot be "replaced" except if it have a bad CRC in which case the fallback configuration will be loaded
the only way to replace the firmware is to run Mesaflash (Path Pilot has a script that does this on startup )

I understand you perfectly, believe me, but I can't do anything but report the facts that happens to me, don't worry I'm already used to the oddest things that happen to me, I'm bewitched.
I mounted the 6i25 board on another PC and after doing the flash it works perfectly after every turning on. Now I have reported the Bios of the old PC to its default configuration and rermounted the 6i25 card on this last, the card works fine, the firmware is not overwritten (sorry I don't know if it's the right word) anymore but the 6i25 is not always initialized with the PC.
I keep testing, maybe I find something badly set on the BIOS...

Nothing in the BIOS can cause reloading of the firmware image in the EEPROM (only Mesaflash can do that)

If the firmware load from EEPROM is unsuccessful at powerup, you will either have an inaccessible card (no DEVID in lspci) or the card will load its backup configuration (there are only 2 possible configurations in the EEPROM, the normal user configuration and the fallback configuration, the default fallback configuration is recognizable because it blinks the red INIT LED continuously and it has only GPIO )

When you say the card is not initialized properly, what does Mesaflash show?
What do the red LEDs light on the card do?