Reproduced this issue by following below steps and verified the same on 3.12.2-15.el7rhgs.x86_64.

Steps:
1) Created a distributed-replicated volume and start it.
2) FUSE mounted it on a client.
3) From mount point created the data set as below,
a) Created a dir named 'master' on mount point and created 8000 empty dirs inside it (dir1 to dir8000)
b) then inside each dir1, created 1000 directories with 1000 files in each directory.
c) Repeated b on dir2..dir10
4) Changed the rebalance throttle to lazy using below command,
"gluster volume set distrep rebal-throttle lazy"
5) Added many bricks.
6) Start rebalance with force option
7) list the directories on master.

In older build, not all directories are listed during rebalance. However, could see all the directories at the end of rebalance.

In the fix build, I could list all the directories and subdirs.

Hence, moving this BZ to Verified.

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHSA-2018:2607