Jenkins job fails to trigger build

[Dylan Maxwell]

Occasionally when I start a build, that job will fail to trigger a downstream job.

If I start the exact job again with the same build it will work correctly. It work right ~80% of the time.

The system log contains no errors around the time of the missed trigger and there is no indication of an error.

The console output when the trigger FAILS is as follows:

09:54:15 Triggering calc-unstable-2_binaries » amd64,debian08,debian_glue
09:54:20 Configuration calc-unstable-2_binaries » amd64,debian08,debian_glue is still in the queue: Waiting for next available executor on debian_glue
10:00:06 calc-unstable-2_binaries » amd64,debian08,debian_glue completed with result SUCCESS
10:00:06 Triggering calc-unstable-2_binaries » amd64,debian07,debian_glue
10:00:11 Configuration calc-unstable-2_binaries » amd64,debian07,debian_glue is still in the queue: Waiting for next available executor on debian_glue
10:07:04 calc-unstable-2_binaries » amd64,debian07,debian_glue completed with result SUCCESS
10:07:04 Finished: SUCCESS

And  the console out when the trigger is SUCCESSFUL is as follows:

11:36:27 Triggering calc-unstable-2_binaries » amd64,debian07,debian_glue
11:36:32 Configuration calc-unstable-2_binaries » amd64,debian07,debian_glue is still in the queue: Waiting for next available executor on debian_glue
11:40:30 calc-unstable-2_binaries » amd64,debian07,debian_glue completed with result SUCCESS
11:40:30 Triggering calc-unstable-2_binaries » amd64,debian08,debian_glue
11:40:35 Configuration calc-unstable-2_binaries » amd64,debian08,debian_glue is still in the queue: Waiting for next available executor on debian_glue
11:49:17 calc-unstable-2_binaries » amd64,debian08,debian_glue completed with result SUCCESS
11:49:17 Warning: you have no plugins providing access control for builds, so falling back to legacy behavior of permitting any downstream builds to be triggered
11:49:17 Triggering a new build of calc-unstable-3_piuparts
11:49:17 Finished: SUCCESS

Notice the warning in the second case: "Warning: you have no plugins providing access control for builds, so falling back to legacy behavior of permitting any downstream builds to be triggered"

Does anyone know what may cause these sporadic failures? Or how to better diagnose the problem?  Or how to correct the above warning?

I am using Jenkins v1.651.1

Any help would be appreciated.

Thanks,

Dylan