It's possible to have pages of sufficient length that generating a PDF from them takes longer than 60 seconds and so runs into the Nginx timeout period in OnDemand. This makes it basically impossible to successfully generate a PDF that the customer can access. Confluence should generate PDFs with a long-running task view so we avoid this.

Workaround
There are two options that you can take as a workaround.

The first option is to split one long confluence document into several smaller documents.

Alternatively, you can use the Confluence Space / Multiple page export tool to export the page without it timing out. Please note, you'll need to have the Export Space permission to be able to do this.