Comment # 7 on bug 1216956 from Takashi Iwai

(In reply to Paolo De Pasquale from comment #6)
> (In reply to Takashi Iwai from comment #5)
> > Download kernel-default-6.6*.rpm from
> >   http://download.opensuse.org/repositories/Kernel:/stable/standard/x86_64/
> > and install it via zypper install.
> > 
> > Note that it's an unofficial build, hence you'd need to turn off Secure Boot
> > if necessary.
> 
> 6.6 works.

OK, then the next TW update kernel should work.

> I'm noticing that - having it installed - I lost any reference from grub to
> the former 6.8.1: is this expected? Can I retrieve that kernel somehow?

It's unexpected.  Are the kernels still there in /boot/*?
You installed with "zypper install", not with "rpm -U", right?