bucket deleted but says orphan bucket

we created default bucket and loaded 1000 docs with expiry 10sec, After the document expired, did a dcp stream with include delete times and enable_expiry on one of the Vbucket.

Then deleted the bucket, created the default bucket, created a collection and loaded some 3 keys with 10s expiry and did a dcp stream with enable_expiry_opcode as false and true and also with and without collections(-c option) using simple_dcp_client.py from pydcp github

commands executed: (created 3 docs on vbucket 0 with expiry 10s and waited for the document to expire then executed the below commands)

1. ./simple_dcp_client.py -n 10.112.180.101:11210 -u "Administrator" -p "password" -b default -v 0 --enable-expiry --delete_times  -c

2. ./simple_dcp_client.py -n 10.112.180.101:11210 -u "Administrator" -p "password" -b default -v 0  -c

3. ./simple_dcp_client.py -n 10.112.180.101:11210 -u "Administrator" -p "password" -b default -v 0 

Then we deleted the bucket and tried loading 1000 docs to the default bucket. the default bucket was deleted but activity in UI shows "orphan bucket:default" as shown in the image.

Found this issue in the build 6.5.0-1914.