[Jepsen] Underflow exception seen while processing {{DCP_BUFFER_ACKNOWLEDGEMENT}}

2021-11-02T06:42:08.608731-07:00 ERROR 64: Exception occurred during packet execution. Closing connection: ThrowExceptionUnderflowPolicy current:4262112 arg:17049478. Cookies: [{"aiostat":"success","connection":"[ {\"ip\":\"172.23.107.227\",\"port\":59326} - {\"ip\":\"172.23.106.61\",\"port\":11209} (System, <ud>@ns_server</ud>) ]","engine_storage":"0x0000000000000000","ewouldblock":false,"packet":{"bodylen":4,"cas":0,"datatype":"raw","extlen":4,"key":"<ud></ud>","keylen":0,"magic":"ClientRequest","opaque":268,"opcode":"DCP_BUFFER_ACKNOWLEDGEMENT","vbucket":0},"refcount":1}] Exception thrown from: ["#0  /opt/couchbase/bin/memcached() [0x400000+0x1339e4]","#1  /opt/couchbase/bin/memcached() [0x400000+0x3e7748]","#2  /opt/couchbase/bin/memcached() [0x400000+0x3e7fa0]","#3  /opt/couchbase/bin/memcached() [0x400000+0x3e81ad]","#4  /opt/couchbase/bin/memcached() [0x400000+0x3e84b4]","#5  /opt/couchbase/bin/memcached() [0x400000+0x29c6bb]","#6  /opt/couchbase/bin/memcached() [0x400000+0x1858ef]","#7  /opt/couchbase/bin/memcached() [0x400000+0x224dc0]","#8  /opt/couchbase/bin/memcached() [0x400000+0x1f793b]","#9  /opt/couchbase/bin/memcached() [0x400000+0x1f8ce0]","#10 /opt/couchbase/bin/memcached() [0x400000+0x1d8ad1]","#11 /opt/couchbase/bin/memcached() [0x400000+0x1d8d63]","#12 /opt/couchbase/bin/memcached() [0x400000+0x1d93eb]","#13 /opt/couchbase/bin/../lib/libevent_core-2.1.so.7() [0x7fc7055a6000+0xed8e]","#14 /opt/couchbase/bin/../lib/libevent_core-2.1.so.7() [0x7fc7055a6000+0x17d01]","#15 /opt/couchbase/bin/../lib/libevent_core-2.1.so.7(event_base_loop+0x3bf) [0x7fc7055a6000+0x1854f]","#16 /opt/couchbase/bin/memcached() [0x400000+0x7c7577]","#17 /opt/couchbase/bin/memcached() [0x400000+0x7c7a46]","#18 /opt/couchbase/bin/memcached() [0x400000+0x7c9406]","#19 /opt/couchbase/bin/memcached() [0x400000+0x1a84d9]","#20 /opt/couchbase/bin/memcached() [0x400000+0x7532b9]","#21 /lib/x86_64-linux-gnu/libpthread.so.0() [0x7fc7062eb000+0x76db]","#22 /lib/x86_64-linux-gnu/libc.so.6(clone+0x3f) [0x7fc703a76000+0x12171f]"]