Trouble with DSC 1616 Wireless Zone—Need Help

I’m dealing with an issue on my DSC 1616 panel. I had a WS4945 wireless sensor on Zone 01 that got water damaged. I replaced it and swapped out the ESN, but I’m running into a strange problem: the panel shows as ready when the door is open, but when I close the door, it goes to “Not Ready.”

I even tried replacing the WS4945 with a new one, but the same thing happens. I haven’t worked on a PC1616 in a while, so I’m not sure what I’m missing.

Could anyone shed some light on what might be going wrong? Any tips or advice would be greatly appreciated!