When you export the data, you send a request to the export module. By default, the connection is active for 2 minutes. If you use a docker image, there is the Nginx server for remapping the incoming requests. And it also has 2 minutes as the default connection time.
In the new export module, the connection timeout is increased to 8 hours. And you can manually set the page rendering timeout.
The new version of the export module has not yet been released, but you can contact the support team, mention this topic and ask for a newer version. It uses Electron for rendering and exporting the data, so you can export huge charts to PDF or export Gantt on several pages.
Here is an article that explains what other features the new export module will have: