I have noticed a similar behavior. In my case when I publish a post from my WordPress “admin” console then the YOURLS entry is made in the database. If I use the iOS app Press Sync, for example, and create and publish a post then the YOURLS entry is not made. If I create my post with Press Sync and save it as a draft and then “publish” it via the admin console then a YOURLS entry is made.
Is this a bug in the YOURLS Link Creator?
For testing I downloaded a different WordPress YOURLS creator plug in and it does not exhibit this problem. Ie., a post created on Press Sync and published directly from Press Sync creates the YOURLS entry. I would prefer to use your plugin as it seems to have more features then the other one I quickly found and installed.
Thank you.