Windows no longer starts following an update

I have a dual boot PC with Ubuntu and W11, it's an HP Elitebook 850 G3
at startup, W10 launches, and if I want to start Ubuntu, I go through the BIOS and I select UEFI-Ubuntu and I arrive at the GRUB menu (I didn't take the time to make it cleaner)
 
here's what's happened to me since September 5:
 
- at startup, Windows starts and launches an update, I restart to use Ubuntu, the Grub menu is not displayed and I get the message
“Verifying shim SBAT data failed: Security Policy Violation
Something has gone seriously wrong: SBAT self-check failed: Security Policy Violation”
then the PC turns off
Since the BIOS, I no longer have the input for W11, so nothing
I can access a Windows repair menu, but nothing worked