WiFi Antenna Installation Issue

[Zydeco]

We need help with our WiFi Antenna. We are using a Bullet 2HP system with a POE injector. We mounted it at the masthead with about 90 feet of Cat 5 cable. (no, we do not have a 90 foot mast - the cable runs down the backstay, then to the middle of the cabin where the POE injector and router are mounted) It worked fantastic for awhile, then went haywire after about a week at anchor. It could still "see" numerous APs and connect, and according to the AirOS software it had a good connection (for example 80 dBm and good TX and RX rates (for example 36 Mbps) but when we opened a browser, it would not open any web pages. From time to time, it would connect very briefly, then stop. We tried different APs, different computers, varios settings on the Bullet, etc but no joy.

We spent last night in a marina and charged the battery bank. This morning the Bullet works perfectly. My guess is that the cable run is too long and the Bullet does not get quite enough power when the batteries are discharged. We have a 440 ah battery bank and it was down about 90 ah when we were having problems with the Bullet. Still reading a little over 12 volts.

We need to be able to use the WiFi antenna when we cruise the Bahamas this winter and we will be anchored for weeks at a time. The batteries will be down as much as 150 ah.

Any ideas?