How to represent a mixed xml node

I'm trying to represent a mixed xml node in JSON schema. The mixed node has multiple attributes and text() contents

Example:

<desc language="en-US">Description text</desc>

I got to here:

"application/xml": {

"schema": {

"type": "object",
"properties": {

"language": {

"type": "string",
"xml": { "attribute": true }

},
"#text": {

"type": "string"

}

},

"xml": { "name": "desc" }

}

}

But the Swagger UI (v3.38.0) generates:

<desc language="string"><#text>string</#text></desc>

Is this a bug in the framework and should #text just always be rendered as text(), is there some kind of syntax missing that allows me to be specific about what #text actually is, is there a different way to do this other than #text?