DigitalOcean App Platform response size limit. Not able to return large files

I have successfully deployed a Python (FastAPI) API on the Digital Oceans Apps Platform. There is a POST API endpoint that returns an Excel file as a response. When the file size is 7 KB, it is returning fine. When the file size is 80 KB, a 0 bytes files gets downloaded.

The cURL I am using is similar to

curl -X 'POST' \
  'https://example.com/api' \
  -H 'accept: */*' \
  -H 'header: value' \
  -H 'Content-Type: multipart/form-data' \
  -F 'myfile=@myfile.pdf;type=application/pdf' \
  --output output.xlsx

When the output.xlsx is less than 10 KB, it is getting saved just fine, however when it is more, the output is a 0 bytes file.

Is there a limit on the response size limit on the DO Apps Platform? Could not find any such thing mentioned on https://docs.digitalocean.com/products/app-platform/details/limits/

The API code is similar to https://fastapi.tiangolo.com/advanced/custom-response/#fileresponse