If you have an active job that does not show up as an option when logging time or searching on the mobile application, this is likely due to there being no phases set up with labor enabled. In an effort to limit how many phases show up in searches on the app, you are able to disable labor for any job phase that is meant to just track materials and/or subcontractors. To track time for any job phases, labor will need to be enabled.
In the Plan&Track section of any job, you can see at a glance if your job phases have labor enabled or not:
If you need to turn labor on for any job phase, first click Switch to Edit Mode at the bottom right of this page:
You can then click Enable Labor for any job phase that should be tracking time. Be sure to click Switch to Active Mode at the bottom of the page when you are done: