Error: "Self-referencing circular pointer"

I get this error when i run:

$ redoc-cli bundle -o dist/docs/index.html docs/openapi.yml
Prerendering docs
Error: Self-referencing circular pointer
    at /usr/lib/node_modules/redoc-cli/node_modules/@redocly/openapi-core/lib/resolve.js:242:31
    at Generator.next (<anonymous>)
    at /usr/lib/node_modules/redoc-cli/node_modules/@redocly/openapi-core/lib/resolve.js:8:71
    at new Promise (<anonymous>)
    at __awaiter (/usr/lib/node_modules/redoc-cli/node_modules/@redocly/openapi-core/lib/resolve.js:4:12)
    at followRef (/usr/lib/node_modules/redoc-cli/node_modules/@redocly/openapi-core/lib/resolve.js:240:24)
    at /usr/lib/node_modules/redoc-cli/node_modules/@redocly/openapi-core/lib/resolve.js:300:45
    at Generator.next (<anonymous>)
    at /usr/lib/node_modules/redoc-cli/node_modules/@redocly/openapi-core/lib/resolve.js:8:71
    at new Promise (<anonymous>)

Here is my file structure:

tree .   
.
└── docs
    ├── iap
    │   ├── paths
    │   │   ├── products.yml
    │   │   ├── product.yml
    │   │   ├── subscriptions.yml
    │   │   └── subscription.yml
    │   └── schemas
    │       ├── filter_product_type.yml
    │       ├── period_type.yml
    │       ├── period.yml
    │       ├── product_currency.yml
    │       ├── product_filters.yml
    │       ├── product_list.yml
    │       ├── product_type.yml
    │       ├── product.yml
    │       ├── subscription_params.yml
    │       ├── subscription_status.yml
    │       └── subscription.yml
    ├── openapi.yml
    └── _schemas.yml // imports all schemas from service schema folder

I checked it many times, there are no circular referencing. And other tools like OpenAPI VSCode Extension by 42Crunch seems to work fine with previews.