Nextjs sourcemaps issue

Hi everyone, I currently have a project using

   "@sentry/nextjs": "~6.12.0",

I rely on withSentryConfig to automatically upload sourcemaps, but i’m not sure when the sourcemaps are being uploaded. Are they uploaded during next build or next export?

Also, I’ve noticed cases where my sourcemaps are broken because they point to js chunks that are hashed, and the hashed version does not seem to have been uploaded. Does anyone know why this would be the case?