Why do immediate function tests have pending results?

Although function tests should be executed very quickly, there are other internal factors that need to be met on the device prior to execution which can delay the execution of the function test. 

Due to these possible delays, we do not wait for the results of the immediate function tests during the initial sync.  If you believe the results could be ready you can request a resync to get results. 

The app will alert you to go and sync the devices for the pending results after the timeout settings you have provided in the app.

To adjust this timeout you can find the setting under:
Site dashboard -> Details -> Edit -> Settings > Test execution timeout (days)