reactjs - nextjs tvinga transpiler es6 till es5 ignorera tsconfig

Nextjs ignorera tsconfig target-alternativet vid kompilering. Es6-klasser och arrow-funktioner transpilieras till funktioner.

När next build skrivs i terminalen

info  - Using tsconfig file: ./tsconfig.json

och path-alias orsakar inget fel. Så min tsconfig tillämpas. Men nextjs transkriberar alla arrow functions, klasser, etc

// tsconfig.json
{
    "compilerOptions": {
        "target": "es2020",
        "lib": [
            "webworker",
            "dom",
            "dom.iterable",
            "esnext"
        ],
        "allowJs": true,
        "skipLibCheck": true,
        "strict": true,
        "forceConsistentCasingInFileNames": true,
        "noEmit": true,
        "esModuleInterop": true,
        "module": "esnext",
        "moduleResolution": "Node",
        "resolveJsonModule": true,
        "isolatedModules": true,
        "jsx": "preserve",
        "baseUrl": ".",
        "paths": {
            "@/*": [
                "./*"
            ],
            "src/*": [
                "src/*"
            ],
        },
        "incremental": true
    },
    "exclude": [
        "node_modules"
    ],
    "include": [
        "next-env.d.ts",
        "**/*.ts",
        "**/*.tsx"
    ]
}