sorry to say I have no solution, but I have the same problem. Have been searching for my configuration error with no luck, so now I am quite happy to have at least found a soul mate :).
I am playing on a new system with OCS 2.6-RC (Apache/2.4.25 (Debian) mod_perl/2.0.10 Perl/v5.24.1) on Debian. So far I thought about vhost problems, but Apache logs show exactly the same behaviour as your system
[Tue Jan 08 19:48:29.984384 2019] [authz_core:debug] [pid 12949] mod_authz_core.c(809): [client 18.104.22.168:39978] AH01626: authorization result of <RequireAny>: granted
[Tue Jan 08 19:48:30.455823 2019] [core:notice] [pid 8423] AH00052: child pid 12949 exit signal Segmentation fault (11)
I am running OCS2.2 on an older system very happily, so I am not so sure there must be a problem with the code.
But I am looking forward to answers from people with knowledge.
Good luck us both.