Json API explorer not working

Problem/Motivation

After updated modules about Json:API, explorer not working anymore.

After some search, I fixed the first visible error with the patch in this issue : TypeError: Argument 1 passed to JsonApiSchemaController

But after applied the patch, explorer still not working. I see in the production website (not already push the update module) the explorer call one time the /jsonapi/schema url. And after update I see more than 300 calls for schemas.

The main difference is in "targetSchema" attribute :
before

"type": "object",
"links": [
  {
    "href": "{instanceHref}",
    "rel": "related",
    "title": "Platform entities",
    "targetMediaType": "application/vnd.api+json",
    "targetSchema": "https://xxxx/jsonapi/platform/platform/collection/schema",
    "templatePointers": {
      "instanceHref": "/links/platform--platform/href"
    },
    "templateRequired": [
      "instanceHref"
    ]
  },
...

And after update

"type": "object",
"links": [
  {
    "href": "{instanceHref}",
    "rel": "related",
    "title": "Platform entities",
    "targetMediaType": "application/vnd.api+json",
    "targetSchema": {
      "$ref": "https://xxxx/jsonapi/platform/platform/collection/schema"
    },
    "templatePointers": {
      "instanceHref": "/links/platform--platform/href"
    },
    "templateRequired": [
      "instanceHref"
    ]
  },
...

Proposed resolution

I propose you an patch quick-fix to prevent this issue.

But, with more background whole feature/project the patch isn't the correct solution.