One PMP 450 not receiving sync from CMM4

I have 4 pmp 450's all connected to a CMM4 with Ruggedized switch and GPS Module. These devices have been connected and working without issue for close to 3 years now. One of the 450's dropped sync and has not gotten it back. I went onsite and tried moving it to a different port, remaking the cat5 connector at the bottom of the tower, and swapping it's connection to the CMM4 with a known working antenna. None of these steps resolved the problem.

Has anyone else ever had only one specific device not recieve sync? the cmm4 is on verson 3.0, and the pmp 450 is 15.1.3