There are a number of timeout settings in Alfresco Content Services that affect the Document Transformation Engine. These are the defaults:
content.transformer.default.timeoutMs=120000
transformserver.transformationTimeout=300
transformer.timeout.default=300
content.transformer.default.timeoutMs is the system transformation timeout (set to 120000 milliseconds by default), but the Document Transformation Engine is controlled by transformserver.transformationTimeout and transformer.timeout.default. This means that with the default settings, Alfresco Content Services stops processing after 120 seconds, whereas the Document Transformation Engine attempts to transform a document for up to 300 seconds and any results returned after 120 seconds are ignored.
If you set the following:
transformserver.transformationTimeout=120
transformer.timeout.default=120
the Document Transformation Engine stops processing at the same time as the default system transformation timeout.