SharePoint List View Formatting @currentWeb Token not being replaced

[Phillip Allan-Harding]

Started seeing today that the @currentWeb token is not being replaced in a custom list view format.

URLs created with the token just contain the literal string"@currentWeb"

e.g. the snippet below results in a link with the URL;

https://tenant.sharepoint.com/sites/contoso/Lists/MyCustomList/@currentWeb/Lists/MyCustomList/DispFo...

{
   "elmType": "a",
   "attributes": {
      "class": "ms-fontSize-xxl ms-fontColor-themePrimary",
      "href": "=@currentWeb + '/Lists/MyCustomList/DispForm.aspx?ID=' + '[$ID]'"
   },
   "txtContent": "[$Title]"
}