Resolved -
Root cause:
The Dockerfile contained npm run build | true instead of RUN npm run build. The | true pattern pipes the build command's output, which has the side effect of always returning exit code 0 regardless of whether the build succeeded or failed. When the build failed (due to a code issue), Docker saw no error, happily continued building the image, and produced a container with no compiled static assets. nginx started up, found nothing in its web root, and fell back to its default page.
A syntax error in the frontend code was shipped to production. The browser failed to parse or execute the malformed code, causing components to not render correctly — resulting in a broken or blank UI for users.
Immediate fix: Replace npm run build | true with RUN npm run build. Optionally add a follow-up RUN step to assert the output directory is non-empty, so even a silent partial build would be caught.
Apr 3, 14:10 UTC