Certainly, this problem occurs with 4-byte characters in some cases.
It is not a problem of the publication export records, but it is due to the public database (MySQL) reading.
We have fixed the bug in the internal reading PDO so now it supports utf8-mb4.
You can update the code using the tool administration 'Update Dédalo code' button as you normally do.
If you do not have access to the panel, ask your administrator to do it