So far I've been unable to find the problem, which occurs with x86_64 (and aarch64), but not with x86 (which has not moved to fltk-1.4).
tce-load and tce-setup are identical in x86 and x86_64 (aarch64 is still using the previous versions)
Reverting to the previous versions of tce-load and tce-setup does not help.
Reverting to the previous version of apps does not help
If I revert to the fltk-1.3 version of apps with x86_64 (and aarch64) then onboot maintenance works as expected.
Is this somehow a problem created by compiling apps against fltk-1.4?
Edit: building apps against fltk-1.3 and fltk-1.4 with x86 (and armhf), both work.
Something to do with apps and 64-bit?