Messages are not moving to the new mailbox server when using the NG mailbox move command. Within the mailbox.log there are a number of warning messages like:
2018-10-03 16:31:41,945 WARN [HSM Blob Mover Copy]  mailbox - The blob item 493665 with revision 849332 of mailbox 9 from volume 1 has been copied, but the source and destination digest differ (lIvhYaIy7QaO+xb9bF8dtuHhbOxwLmaXvpkC2fHE7ds= => v+ptos02+emht3zJwISsh58gjNBxGuIZzUKh15hyoAc=). This item will be skipped.
The cause of the issue are incorrect digests values. Upgrading to 8.8.8 Patch 10 or higher will install a new command to fix this incorrect digests values. Once upgrade, you can run:
zxsuite hsm doCheckBlobs start fix_incorrect_compressed_digests true