These are user to user forums so there is nothing for those who post here to "fix", sorry!
If you can give rather more details about exactly which Revolta 2 voices you are using it might be possible for fellow-users to test similar settings ob theri machines to see whether they can reproduce the problem.
If they can, then you will need to create a Support Ticket and ask that Magix support staff look into this.
@Tomasz-Szwej Click on the SUPPORT link at top of this page and then select your product. On the next page scroll down until you can click on Contact Support and create your ticket.