I have Microsemi BR246-S0233. As is, the resistance between the X2 (GND) and signal line (e.g. A2) is OL. However, when I power it up (X1 = 25VDC), leave it for 5 minutes and power off, then straight away measure the resistance between X2 (GND) and the signal line A2, the resistance is now 5Mohm. This resistance gradually increases over 5 minutes or so. Why does this happen???