Unable to delete connection from API

[stcbus]

I get an internal error similar to others posted for other editing.

{
"message": "Unexpected internal error",
"translatableMessage": {
"key": "APP.TEXT_UNTRANSLATED",
"variables": {
"MESSAGE": "Unexpected internal error"
}
},
"statusCode": null,
"expected": null,
"patches": null,
"type": "INTERNAL_ERROR"
}

{{baseURL}}/api/session/data/{{dataSource}}/userGroups/:userGroup in bruno with a valid auth token. I have tried changing the parmaeter to the group ID but that just gives me "can't find". Tried with both disabled and no disabled group.