Rollup - Error in readListPart()

@balazshoranyi I actually just started seeing this again on my current cluster, exactly as originally posted.

Really, I do not even know if it is causing a devastating issue or not! It would be very difficult for me to identify if a few of my billions of values were missing or something.

Current cluster specs:

Dgraph version   : v21.03.1
Dgraph codename  : rocket-1
Dgraph SHA-256   : a00b73d583a720aa787171e43b4cb4dbbf75b38e522f66c9943ab2f0263007fe
Commit SHA-1     : ea1cb5f35
Commit timestamp : 2021-06-17 20:38:11 +0530
Branch           : HEAD
Go version       : go1.16.2
jemalloc enabled : true

3*zero(4c, 10GiB ram)/ea shardReplicas=3
12*alpha(16c, 32GiB ram, 2TiB disk)/ea