V3: cloudinary upload returns "Invalid Signature" error

System Information
  • Strapi Version: 3.6.8
  • Operating System: MacOS
  • Database: SQLite
  • Node Version: 14.8.3
  • NPM Version: 8.1
  • Yarn Version: 1.22.17

I am trying to get cloudinary working on a v3 Strapi. While v4 works great, v3 fails with this error message, when I try to upload something:

Error: Error uploading to cloudinary: Invalid Signature 2eae680bc99bb3abd6373e6d6399b9b4f0d5b426. String to sign - 'public_id=peaks_contextmenu_events_overlapping_4ed030e1be&timestamp=1646957735'.
    at Object.unknownError (/Volumes/_III_/Z_WWW/_ZZZ PoD/pod-strapi/node_modules/strapi-plugin-upload/errors.js:16:17)
    at /Volumes/_III_/Z_WWW/_ZZZ PoD/pod-strapi/node_modules/strapi-provider-upload-cloudinary/lib/index.js:35:38
    at /Volumes/_III_/Z_WWW/_ZZZ PoD/pod-strapi/node_modules/cloudinary/lib/utils/index.js:1243:14
    at IncomingMessage.<anonymous> (/Volumes/_III_/Z_WWW/_ZZZ PoD/pod-strapi/node_modules/cloudinary/lib/uploader.js:507:9)

My configuration is that of the documentation:

// config/plugins.js

module.exports = ({ env }) => ({
  email: {
    provider: "console",
  upload: {
    provider: 'cloudinary',
    providerOptions: {
      cloud_name: env('CLOUDINARY_NAME', 'blabla'),
      api_key: env('CLOUDINARY_KEY', '123123123'),
      api_secret: env('CLOUDINARY_SECRET', 'qweqweqweqwe'),
    actionOptions: {
      upload: {},
      delete: {},

I do not use any middleware nor did I do anything in the extension folders. (I had AWS working and SFTP, so the system itself works; it is really just the cloudinary plugin.)

Any idea what this error means?

@strapi-employee @community_stars @Fabio_Strapi1