I enabled the plugin and only gave some people permissions. Someone who does not have permission told me that their large furnace was turning on and off. I suspected this plugin since it was the only new plugin I added recently so I disabled it.

After disabling this plugin the player said the furnace stopped turning on/off. 

Is it possibly related to this plugin?

I don't know any reason that it would be related. All this plugin will do is set the isMonitorable property of the container to true or false. The only game code that checks that property is for determining whether a storage monitor can be deployed. In theory, a plugin could be looking at that property and causing this behavior but that is unlikely.

If there is any sort of unexpected plugin interaction, I would expect it would be due to another plugin changing behavior if the furnace has a child entity for example, but that would only be an issue when there is a storage monitor deployed, which was not the case in the example you mentioned.

Do you have the Lights On plugin? I believe it has a feature to turn furnaces on/off with the day/night cycle. There have been some updates to it recently so there may be a new bug or something. Somebody else had issues with mixing tables getting stuck on because of that plugin.

Thanks for the quick response. Yeah, I was scratching my head since I couldn't believe it would be this plugin.

I do use NightLantern which does what you're suggesting. I'm going to see if the furnaces are turning off/on when night/day happens. 

Thanks for the direction.