You will not necessarily receive an alert for every job available. Below are possible reasons for this:

1. Filters: The job did not meet your keyword or duration filters. For instance, if you are set for Full Day Jobs Only, then you will only be alerted to jobs that fit that criteria. Click Job History to see if any jobs have been detected where alert sent is Np. It is possible you have filters set in Sub Sidekick and/or your substitute-service account (Aesop, SubFinder, SubFinder Elite, SmartFindExpress). Check both sites' preferences to make sure you still want to keep those filters. Update as needed.

2. Schedule Conflict: If you are already scheduled for another job, you will not receive any alerts for jobs that conflict with the existing job. 

3. Job Marked 'Locked'/Unavailable: The job was marked as unavailable by the substitute-service (Aesop, SubFinder, SmartFindExpress), meaning that the job is locked or currently unavailable for acceptance. Once the job becomes available, you will be notified.

4. District/School Preferences: The substitute-service may use algorithms to only show a job to substitute teachers that are on a preferred list, have a specific qualification, or other criteria defined by the school district. The job may also be assigned directly to a specific substitute teacher without the job ever being put into the system. 

5. TimingBecause Sub Sidekick is only able to check for jobs at a set interval (usually about every 60 seconds depending on the sub-service), a job may have appeared and disappeared between that interval. This doesn't happen often, but because of this, it is possible for a job to become available and then accepted by someone else before our server can detect it. There is no way to change this interval because it is determined by the substitute service and our server settings. 

For useful tips on how to quickly accept jobs that DO become available, read further here: What's The Fastest Way To Accept Jobs?