[CookiesAsync](https://playwright.dev/dotnet/docs/api/class-browsercontext#browser-context-cookies) has an incorrect return type.. it is actually `Task<IReadOnlyList<BrowserContextCookiesResult>>` (see [here](https://github.com/microsoft/playwright-dotnet/blob/main/src/Playwright/Core/BrowserContext.cs#L379)) Docs:  Package: 