The problem comes from trying to handle data types in both database-specific and database-independent formats. I’m going to look at better ways of handling it with 3.2. I created https://liquibase.jira.com/browse/CORE-1695 to track the issue.
For now, you’ll have to fix the generated xml to “timestamp without timezone” and then it should work.
Or you could create an extension (liquibase.org/extensions) that overrides the TimestampType class to return “TIMESTAMP” instead of “TIMESTAMP WITH TIMEZONE”