We are all users here. You’re asking in the wrong place. Have you submitted an Issues ticket for the developers to look at? You are going to need to supply a lot more information for them to replicate and trouble shoot this problem.
Outbound CNAM is a third party module, not supported by the project devs. As the author, I don’t have time to investigate this at present, nor do I know enough about utf8 to suggest places to look for the issue. You can open a ticket here and add any details and/or fixes you come up with.