This still happens when booting the latest Focal ISO images (20200417), see the attached screenshot. The problem appears to be racey, as sometimes plymouth does start in time, and the graphical background is shown, sometimes it does not, and the installer boots in text mode. I can reproduce the problem on both actual hardware and QEMU.
The problem it likely caused by the fact that plymouthd is not ready yet when `plymouth show-splash` or casper try to connect to it. If this is the case, booting with plymouth:debug wouldn't really help, as there is nothing to connect to. ** Attachment added: "plymouth-connection-refused.png" https://bugs.launchpad.net/ubuntu/+source/plymouth/+bug/1871717/+attachment/5357134/+files/plymouth-connection-refused.png -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1871717 Title: spinner theme, sometimes does not render splash without output To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/plymouth/+bug/1871717/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs