Comment # 12 on bug 1047256 from Zhao Qiang ������

(In reply to Milan Hejpetr from comment #11)
> Not any progress?
> Problem persists :-(

nd we know that the premise condition of Plymouth is kernel mode setting (KMS)
works fine, but both Nvidia and AMD proprietary drivers don't support it well.
and these drivers are not open source, unfortunately. So I think the only thing
we can do is disable Plymouth in this scenario.

You said that with kernel's original display driver, Plymouth still can not
work, This is a problem. but the proprietary driver will install kernel module
too, have you tried clean install and update without Nvidia driver?