CentOS - Aug 2021 - I get "bad shim signature" booting with Secure Boot enabled

Hi,

If I enable Secure Boot in my UEFI I get this error (just after
selecting Centos from the grub menu)

grub-core/kern/efi/sb.c:151: bad shim signature
grub-core/loader/i386/efi/linux.c:208: you need to load the kernel first

Can someone explain to me why I get this, please? And what can I do to
get Centos to boot with Secure Boot?

My system:
NAME="CentOS Linux"
VERSION="8"

CentOS Linux release 8.4.2105

Thank you.