The most likely cause of that error message would be making the API call with a version lower than 2024-01, as that’s the version when the query filter got added to Pricelist.prices. This can be confirmed by adjusting the version number at the top left of the dev docs page for the object:
Looking at the screenshot you provided of the ‘Event Version’ selector, that only applies to things like webhooks that are sent out and not to live API calls being made.
The version used for live API calls is determined by what version is specified in the URL when each API call is being made, here’s the GraphQL Admin API endpoint docs which mention that:
When using a library it might not be clear what URL is being used for the API calls as the library handles it behind the scenes. However, we don’t provide direct support for the libraries so you’d want to check the docs from wherever you got the library for how to specify which API version is being used for the calls.
This is important because API version changes occur every 3 months so it’s recommended to keep up to date with the release notes and keep incrementing the API version called every quarter.
Here’s more info on API versioning in general and the release schedule, with the oldest served being a max of 1 year old: