Hello, HeliCrashEvent looks at the Minimum and Maximum time config values for time between events. They are labeled as "Minimum time between events(minutes):" & "Maximum time between events(minutes):". By default it's set to 60 and 180 which is between 1 and 2 hours. You can try deleting the config file and reloading the plugin to reset it back to defaults in case there's a problem with your config.
Please also try restarting your server if you haven't in some time. There was an issue in the past were a coroutine wasn't being unregistered properly when the plugin was unloaded. As a result, it would actually cause the event to still try to run after the plugin is unloaded. If you reloaded the plugin, it would create a duplicate coroutine which resulted in the event starting more often than it should. Based on you describing it still trying to run after unloading, it sounds like this is what's going on. This is fixed in the current version but does require a server restart to remove the duplicate coroutine that's running.