Failed to load config.yml error message when first logging on to deployed site

**Describe the bug**
When deploying a project using DecapCMS, the first time you go to /admin/, an error message shows reading:

_Error loading the CMS configuration_
_Config Errors:_

_Error: Failed to load config.yml (404)_

_Check your config.yml file._

It seems as if this is because the URL isn't formatted correctly. Going to /admin/ redirects me to:

> https://www.domain.com/admin#/

When instead I should go to

> https://www.domain.com/admin/#/

**To Reproduce**

1. Go to a project using Decap, without having logged in before (clearing cookies may help with this)
2. Navigate to the /admin/ route
3. Note the above error message, with the document URL path reading _/admin#/_
4. Change the path to _/admin/#/_
5. Note that this now works

**Expected behavior**
For a user to immediately go to _/admin/#/_

**Screenshots**

Broken path and error:

**Applicable Versions:**
- Netlify CMS version: ^2.0.0
- Git provider: Github
- OS: Windows 10
- Browser version Firefox 115.0.3 64bit
- Node.JS version: v20.3.1

**CMS configuration**
May not be relevant, as it's been replicated with a range of CMS configurations, however:

_backend:_
_name: git-gateway_
_branch: main_

_local_backend: true_
_logo_url: https://codestitch.app/frontend/images/logo.png_

_media_folder: "public/assets/images/blog"_
_public_folder: "/assets/images/blog"_

_collections:_
_- name: "blog"_
_label: "Blog"_
_folder: "src/content/blog"_
_create: true_
_slug: "{{slug}}"_
_fields:_
_- { label: "Title", name: "title", widget: "string" }_
_- { label: "Description", name: "description", widget: "string" }_
_- { label: "Author", name: "author", widget: "string" }_
_- { label: "Date", name: "date", widget: "datetime" }_
_- { label: "Tags", name: "tags", widget: "list", default: ["post"] }_
_- { label: "Featured Image", name: "image", widget: "image" }_
_- { label: "Image Caption", name: "imageAlt", widget: "string" }_
_- { label: "Body", name: "body", widget: "markdown" }_