Be sure the magnet is well away from the switch, several inches may be necessary for a wide gap magnetic switch. If moving the magnet away does not report a state change, disconnect one of the wires from the switch. If a state change is reported when the wire is removed, the magnetic switch is not working.
Could be the EZIO6I is not reporting a state change. There is an option “Broadcast Status Chg” which must be set for the EZIO6I to send those Status Change messages Indigo is using to report state changes. Did you set that option through Indigo or the Simplehomenet Utility Suite? Using the SHN Utility the option can be changed temporarily by doing a “Write” of the Configuration Register with the Broadcast Status Chg option set. This setting is made permanent by clicking on the yellow “Save Changes” button. Don’t know what the process is using Indigo. Also, if you link an Insteon device to the Input, the Status Change message is suppressed, even if the Broadcast Status Chg option is set.
You can try unplugging the EZIO6I but if the Broadcast Status Chg option was not set permanently, the option will be lost when power is removed.
Does Indigo have a mechanism for displaying Insteon traffic? If so you want to look for a Status Change message.