ps: incomplete output with --sort and -H

Combining ps options --sort and -H results in fewer lines than expected despite an exit status of 0. For example

$ ps --version
ps from procps-ng 4.0.4
$ ps -A -H | wc -l
202
$ ps --sort "start_time" -A -H | wc -l
109

Downgrading to procps-ng 4.0.3 does not help but downgrading to 3.3.17, the next prior version in Arch Linux, results in the expected behavior:

$ ps --version
ps 3.3.17 from procps-ng 3.3.17
$ ps -A -H | wc -l
202
$ ps --sort "start_time" -A -H | wc -l
202