If you have looked at your message center lately you will have seen a new message – “We’re making a change to Project Online”. The detail view will show you:
On February 9, we’re making a change to Project Online, to improve project creation and publishing performance. You are receiving this message because our reporting indicates one or more users in your organization are using Project Online. The change will make it so that enterprise projects are not synchronized with SharePoint tasks lists, by default. If you still want enterprise projects to synchronize with SharePoint tasks lists, you can turn this setting back on by going to Project Web App (PWA) Settings > Connected SharePoint Sites > Settings, and selecting the ‘Sync Enterprise Projects tasks to Tasks List’ check box.
The additional information link will take you to the original announcement of the change – on the Project blog last October - http://blogs.office.com/2014/10/21/performance-scale-improvements-project-online/?WT.mc_id=MC02022015ProjectPerformance
We are not taking anything away – just changing how things work by default, to ensure that you are making a conscious choice to use this feature – as it is quite resource intensive and we want to be sure the overall experience with Project Online is a good one!