Jira Insight - Rest API - Invalid UTF-8 middle byte

I’ve encountered an error when I try to create objects in my Jira Insight instance. Whenever there are some sort of a “special character” in any of the attribute values I do get an Invalid UTF-8 middle byte 0x?? error

Does anyone know which encoding is the REST API body suppose to be in in order for it to pass the encoding check? I’ve had similar issues but with Jira and Confluence where the body need to be HTML encoded.

The Jira Insight attributes are of the default text type and I’ve noticed that the following symbols has been an issue (-_?åäöé) I’ve managed to convert them to Windows-1252 encoding but it only helps in some cases and some cases actually converts the value to an disallowed symbol, making the whole convertion a nightmare.

Example of error message:

{"errorMessages":["Invalid UTF-8 middle byte 0x3f\n at [Source: (org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream); line: 72, column: 85] (through reference chain: com.riadalabs.jira.plugins.insight.channel.web.api.r

Would appreciate any help
// Tony