Getting incorrect line number from source-map for React component

I'm struggling to make sense of source map for a next.js app. My goal is to be able to remotely log a client error and determine where it came from in the source. I'm using the source-map npm library. I've created a page that forces a react error in production.

When I force the error in Chrome. I see this:

Error: render error
    at n4-test-error (test-error.tsx:7:11)

which is perfect. Clicking on the file name, I go right to the correct line in the source. But I need to be able to get that when it's another user, so I send the error information to our log server.

The logs show an error like this:

Error: render error
 at n4-test-error (https://www.my-domain.com/_next/static/chunks/pages/_app-4699402e2687df60.js:37:430129)
    at https://www.my-domain.com/_next/static/chunks/pages/_app-4699402e2687df60.js:63:14958
    at section
    at section
    at container (https://www.my-domain.com/_next/static/chunks/pages/_app-4699402e2687df60.js:37:289776)
    at https://www.my-domain.com/_next/static/chunks/pages/_app-4699402e2687df60.js:63:14958

_app-46999... is the same file that Chrome devtools indicates is the source map.

So I fetch that map and feed it to new sourceMap.SourceMapConsumer.

When I call getOriginalPositionFor({ line: 37, column: 430129 }), I get:

  source: 'webpack://_N_E/src/components/bloks/n4/test-error.tsx',
  line: 4,
  column: 38,
  name: 'React'
}

If I call consumer.sourceContentFor that file, I do see the full original source of it which matches what I see in Chrome. But the line number is wrong. It should be line 7.

Why does Chrome get the exact line number, but source-map is off? In this contrived example, it's close enough, but other real-world situations it sometimes isn't even in the right component file, despite the stack showing the name of the component.

I did the same test for an event error rather than a render one and in that case, I did get the exact line number. I'd just like to be able to programatically what Chrome seems to be able to given the same sourcemap.

Any ideas?

Update: I did some more research and it turns out I was logging the errorInfo passed to componentDidCatch, but that shows the component stack which has different line numbers than error.stack. Once I used the line and column from error.stack, my results matched Chrome.