Ventoy USB fails to boot

[MR ZenWiz]

I just built a brand new USB drive with ventoy 1.0.90. the optio to
support secure boot is set.

However, when I try to boot it in my laptop, it gets secure boot
validation failures and refuses to boot from the USB drive.

I have an older USB drive I did this on before and it was working
(haven't verified that it still does).

Any ideas what might be wrong?

The laptop is an LG Gram 17Z90N (Gen 10 i7, 16GB RAM, 512GB SSD) that
boots Xubuntu 22.04.2 and Windows 10 with equal ease.  I want a
working backup bootable USB drive for other installations should I
need them.

???

Thanks.

Mark