Time/Date jumping around

[Sunbow]

Connected to ST1 - ST5000+ Autopilot (powered off, never used); Old Autohelm compass indicator (buried in a cabinet, used only to interface WH Autopilot FG-100 Flux Gate Compass), six ST-60+ Graphic Displays, ST60+ Tridata, ST60+ Wind, and an ST60 Multi. My computer (no internal GPS) is also interfaced, connecting a Icom M710 and Pactor II modem, but they are all also normally powered off.

There are five GPS sensors - the e7 Data Master and e95 in the pilot house, an e7 in the cockpit at the base of the mast, the RS130 GPS sensor, and the AIS 650.

After reading your response, I disconnected the RS130 GPS and the ASI 650 from the converters, and set the cockpit e7 as primary GPS with the other two displays turned off (both autopilots are off as well, just one of the two fluxgate compasses is turned on for the ST1, the second compass is powered on with the WH pilot and connected to it only). Set the data source for GPS and Time to the cockpit e7.

The time is still jumping around, and the set time/date control was erratic when I initially set it to 12 HR -4UTC took several tries to get it to take.

Any other suggestions?