1) Take the standard .ks file fedora-live-kde.ks from spin-kickstarts
2) Build a livecd .iso image with livecd-creator
3) burn it on usb key with home.img file encrypted by command livecd-iso-to-disk
4) Try to boot from the key

Normally, plymouth should ask for a password with small grey input window in the center of the screen to open the home.img file. At least this happened until F26 and should happen now. However, the small window appears for a second and then disappears without leaving the possibility to type in anything. The system locks (graphical interface) then and does not proceed with boot (one can login in command line)

The "guilty" line in .ks file is
plymouth ask-for-password --command="cryptsetup luksOpen \$homedev EncHome"
Disabling it allows to boot smoothly. Replacing it with any other plymouth functionality like "plymouth display-message" or "plymouth ask-question" has the same effect.

If boot is interrupted Alt-F2 and I have access to the system in /var/etc/message the following can be seen at the moment where

error: unexpectedly disconnected from boot status daemon

In some thread found an idea that plymouth is started before the boot process finishes or so, but can't see what I can do.

The problem is actually present in LiveCD since F26. Hoped that it would be resolved in F29 and since it isn't, will raise the question. Somehow, it blocks one of the main functionalities of livecd which is to have persistent encrypted home.

Any help is greatly appreciated