The fact that 1523194 has been assigned to partman-crypto indicates the underlying cause _could_ be there.
However the ubiquity-frontend-gtk does NOT suffer the symptoms that ubiquity-frontend-kde does. Therefore I wonder if ubiquity-frontend-gtk has been modified to accommodate, and I hope the bug you raised in the KDE tracker gets some traction so that ubiquity-frontend-kde can also be made to work around the underlying issue.
The fact that 1523194 has been assigned to partman-crypto indicates the underlying cause _could_ be there.
However the ubiquity- frontend- gtk does NOT suffer the symptoms that ubiquity- frontend- kde does. Therefore I wonder if ubiquity- frontend- gtk has been modified to accommodate, and I hope the bug you raised in the KDE tracker gets some traction so that ubiquity- frontend- kde can also be made to work around the underlying issue.