scfg, echocfg, uedit etc blank screen over X

Not sure when this first started happening, but running scfg, echocfg and uedit as a remote X app is giving just a black screen.

When running through strace it seems to loop around

clock_nanosleep(CLOCK_REALTIME, 0, {tv_sec=0, tv_nsec=1000000}, 0x7ffdc796c770) = 0 select(6, [5], NULL, NULL, {tv_sec=0, tv_usec=0}) = 0 (Timeout)

Though not sure if that's any use.

It starts fine with scfg -iD -iC etc.