When using left align, text is shown as centered. When using center align, the text is left aligned.
If the alignment is set to left, the test email shows it centered, and the opposite occurs when aligned to center. We have only received a handful of instances of this occurring, but we would recommend you check the test email before sending the final campaign until this is resolved.
There is currently no known workaround or resolution for the issue. Please check the current status of this issue on the Known Issues Tracker. (Issue ID: CSUP-523)