Schema Generator not recognize UTF charactors.

hello. I manually created the following schema and loaded it into the Schema generator in RankMeth. Screenshot->

{
"@context":"https://schema.org",
"@type":"ItemList",
"itemListElement":[
{
"@type":"ListItem",
"position":1, "url":"https://example.com/%eb%b2%a0%ed%8a%b8%eb%82%a8-%ec%97%ac%ed%96%89/"
}
]
}

But if you check the actual source code, it looks like this

"@type":"ItemList","itemListElement":[{"@type":"ListItem","url":"https://example.com/89/"}]}]"

Can you tell me if there is a workaround for this issue?

Thanks