I kept checking for things and eventually found the log file EOC.PollingService.log. In it I saw that the NPM01 NPM job was found but had no LastPoll timestamp. This confirmed the processing was not completing. Since adjusting the polling interval wasn't helping I restarted the 'Solarwinds EOC Host Services' and this seems to have cleared up the issues with NPM and Wireless Module.
What I found:
2015-02-21 00:02:18,737 [10] 1 Orion.Poll INFO SolarWinds.EOC.PollingService.JobUpdater - Orion: 1 Module NPM Found True Created 02/20/2015 23:57:23 LastPolled JobID 53044cf3-613b-426f-8438-bc469c3c599a JobType Orion.Module.NPM
What it should show is a time between LastPolled JobID.
Example of what it should show:
2015-02-21 00:07:17,031 [10] 1 Orion.Poll INFO SolarWinds.EOC.PollingService.JobUpdater - Orion: 1 Module NPM Found True Created 02/21/2015 00:02:18 LastPolled 02/21/2015 08:02:48 JobID 90a31ebe-11a9-43df-a06e-6bcd657718d7 JobType Orion.Module.NPM
For now it looks to be working. I just can't find a reason why it wasn't completing the polling before. My other smaller NPM server seems to be having no trouble and always hits 100%.