UI shows 104k mutations remaining when creating indexes on empty bucket

When we CREATE indexes with defer build true, on a bucket with 1 scope and 100 collections and 0 documents , /stats API on one of thee indexer nodes returns this :

"bucket-1:scope-1:collection-14:index14-2:num_docs_indexed": 0,

"bucket-1:scope-1:collection-14:index14-2:num_docs_pending": 104448, 

"bucket-1:scope-1:collection-14:index14-2:num_docs_processed": 0, 

"bucket-1:scope-1:collection-14:index14-2:num_docs_queued": 0, 

"bucket-1:scope-1:collection-14:index14-2:num_flush_queued": 0,

which is also causing the UI to display - 104k mutations pending

This should ideally be 0 mutations pending (as we never loaded the bucket with any documents since the beginning of the test) 

logs : 
https://cb-jira.s3.us-east-2.amazonaws.com/logs/CLI/perf-create-ddl/collectinfo-2021-05-18T054915-ns_1%40cen-s705.perf.couchbase.com.zip
https://cb-jira.s3.us-east-2.amazonaws.com/logs/CLI/perf-create-ddl/collectinfo-2021-05-18T054915-ns_1%40cen-s708.perf.couchbase.com.zip
https://cb-jira.s3.us-east-2.amazonaws.com/logs/CLI/perf-create-ddl/collectinfo-2021-05-18T054915-ns_1%40cen-s709.perf.couchbase.com.zip
https://cb-jira.s3.us-east-2.amazonaws.com/logs/CLI/perf-create-ddl/collectinfo-2021-05-18T054915-ns_1%40cen-s710.perf.couchbase.com.zip
https://cb-jira.s3.us-east-2.amazonaws.com/logs/CLI/perf-create-ddl/collectinfo-2021-05-18T054915-ns_1%40cen-s712.perf.couchbase.com.zip
https://cb-jira.s3.us-east-2.amazonaws.com/logs/CLI/perf-create-ddl/collectinfo-2021-05-18T054915-ns_1%40cen-s723.perf.couchbase.com.zip