The slightly out of date version I'm running (0.9.2) has no problem with this list.
The Reply, Reply All both go to the list, empty CC. The Reply List function does the same thing.
I write this mail with 8.2: Replay, Replay All and List all go to the list, one difference is that Replay uses "Roundcube Users mailing list users@lists.roundcube.net" and the two others uses the plain mail address: "users@lists.roundcube.net"
For me, this is wrong! what I would expect is that "Replay All" goes to both, the list and the sender in CC.
I use normally Kmail and this works the most correct for me, it even provides "Replay to Sender", additionally to the three others.
Andreas