PMP 450i 900 MHz Access Point uGPS Sync Issue

Products PMP
1

So we have an issue regarding the use of a uGPS unit on a tower where we have (2) uGPS units and (4) PMP 450i 900 MHz access points with (2) access points per uGPS unit.

Three of the access points have been operating as expected but we have had one that has shown a lot of random disconnects and I may have found out why but I need to understand the actual problem more. The access point in question seems to be having communication issues with the uGPS unit as the "Invalid Message Count" parameter under "Sync Status" has over 37,000 where as two of the other access points have less than 3,000 and the other less than 8,000. The access point that is showing over 37,000 invalid messages also displays "00/00/0000" for the GPS Date and the GPS Time value is usually behind by two or more minutes more often than not. Even the longitude, latitude, and height values don't remain perfectly in-sync but the longitude and latitude only vary by small amounts which is probably to be expected but the height seems to vary by a few meters or more. Another notable detail is that under the "GPS Receiver Information" field it only shows "Canopy UGPS (GPS + GLONASS)" where as the other three access points show the entire block of information regarding the software version and what not of the uGPS unit.

This seems to clearly indicate that there is a communication problem between the uGPS device and the access point. My initial suspicion is that it could be related to the custom cross-over cables that we usually make to connect the devices together but since I recently lost a uGPS unit due to a factory defect involving an improperly installed seal I want to make sure that this isn't indicative of other known issues possibly regarding moisture inside of the uGPS unit as the one we recently lost had a large amount of water inside of it due to the bad seal.

For reference I have attached screenshots of the sync status page from the two access points that share the uGPS unit in question.

Has anyone seen this particular issue before and if so what were the suspected or known causes of this issue?