Azure Data Factory / Self-Hosted Integration Runtime / ODBC / Connection String In a Parameter

Question

Hey,

Here's what we're trying to do:

1. Got an ADF
2. Self-Hosted Integration runtime, hosted in a Windows VM with an ODBC Driver installed
3. Trying to pass ODBC Driver connection string as a parameter

JSON for the Linked service looks like this:
{
"type": "Microsoft.DataFactory/factories/linkedservices",
"name": "IntacctODBC",
"properties": {
"type": "Odbc",
"typeProperties": {
"connectionString": "@linkedService().conString",
"authenticationType": "Anonymous"
},
"connectVia": {
"referenceName": "DataLakeIntegrationRuntime",
"type": "IntegrationRuntimeReference"
},
"parameters": {
"conString": {
"type": "string",
"defaultValue":" "
}
}
}
}

Test works fine, also, if I enter the connection string manually, or pull the value from the key vault - everything works. My goal is being able to iterate through a collection of connection strings that are not in key vault.
When the configuration is published to the IR, the following message is shown.
Failed to encrypted linked service credentials on self-hosted IR 'DataLakeIntegrationRuntime', reason is: InternalServerError, error message is: Internal Server Error..

Please advise