BIOS firmware upgrade does't work on Dell Precision 7520

Hi all,
I have a Dell Precision 7520.
This laptop is running Windows 10 Professional 21H2 and Dell Hardware diagnostic did not alert me about any trouble.

I tried to execute BIOS upgrade without success today, in fact every time BIOS .exe package restart the system,
but it never flashing the new BIOS release. Windows 10 started after a few seconds after Dell logo.

In this moment my laptop is running BIOS 1.17.0 and I would upgrade it to the latest release  (1.26.0)

I already tried the following steps today without success:

• I tried to run BIOS executable file with different users on my computer
• I tried to run different BIOS file executable (different BIOS update version)
• I tried to flash the same BIOS release running in this moment (BIOS 1.17.0)
• I tried to execute BIOS upgrade using USB pendrive from boot menu
• I tried to reset default settings of my BIOS and run again the executable tool

I always runned software update "As Administrator".
In my case BIOS has got Admin password and I disabled it, however the issue persist.
What can I do?

Thanks for your help!

Federico