Size be More Larger When Restore Data

Hello,

I have an issue with Zextras backup 2.6.4 and Zimbra 8.8.8
Now, I am migrating an email server from zimbra 8.5 to 8.8.8 using a different server
On the old server, data of about 400 gb, but when in the restore on the new server, its data becomes 1 TB and the restore process is not finished yet
On the old server, example.com domain as primary and example.co.uk as an alias, but on the new server, the position is reversed, so the restore position is to the domain alias on the new server
Now, I must deduplicate mailbox for save space disk
Are there any bugs or errors when doing data restore?