It is due to how Next.js handles Typescript and its build process. In Next.js, there are a few reasons:

1.Server-Side Rendering: this sometimes lead to type errors not being immediately visible in the browser since the code may execute without being fully type-checked in the same way as in a client-rendered React app. 2.Type Checking Behavior: If you're running the development server with next dev, TypeScript errors might not break the development server but will show up in the terminal where the Next.js process is running. 3.Typescript Configuration: Just ensure that in tsconfig.json the strict option is enabled, which will enforce stricter type checks throughout your application. 4.Next.js Type Checking: enable type checking using the next dev command by adding the --type-check flag, however this may not be the default behavior..

The way to enable type errors in Next.js

1. tsconfig.json: { "compilerOptions": { "strict": true, // other options } }
2. Run Type Checking During Development: npx next build && npx next dev
3. The change in the package.json: "scripts": { "dev": "next dev", "type-check": "tsc --noEmit", "dev:check": "concurrently "npm run dev" "npm run type-check"" } for this, u will need to install concurrently to run both commands simultaneously.