I fix this by comment out the line

export const runtime = "edge"

at apps/nextjs/src/app/api/trpc/[trpc]/route.ts

I know it's something like next trying to run backend code in frontend like others say. But it's not working for me when I try put net: false in next.config.js.

Then I compare a working project with the not working project line by line. I found out the working project has the above line disabled. Just like magic.