Growing queue on 2 of 11 nodes on a xdcr-cluster. Seeing constant replicator crash on xdcr-cluster

System Test

Front end load @ 10k on both the clusters.
Bidirectional replication on-going on the cluster.

Deleted replication and recreated replication after a few hours, replication started from last checkpoints.

Most of the nodes, except 2 have successfully replicated data.

SAmple output from logs
debug.4:=========================CRASH REPORT=========================
debug.4- crasher:
debug.4- initial call: xdc_vbucket_rep:init/1
debug.4- pid: <0.4116.455>
debug.4- registered_name: []
debug.4- exception exit: {function_clause,
debug.4- [{couch_api_wrap,'get_missing_revs/2-fun-1',
debug.4- [400,
debug.4- [

{"Cache-Control","must-revalidate"}

,
debug.4-

{"Content-Length","50"}

,
debug.4-

{"Content-Type","application/json"}

,
–

Adding more logs from both the clusters.