Raymarine SeaTalk NG issue

[Mazu]

Finally got the boat in the water after a loooooong refit and now going through the systems to correct my mistakes...... I’m having an issue I can’t figure out.
Connecting Raymarine rs125 gps antenna to C80 chart plotter.
I’m coming out of the 3 wire Seatalk port on the C80 into a Seatalk NG converter. If I connect this to either of the white NG ports adjacent to the center port I get the solid green indicator on the converter. I then connect the rs125 to the center port. The RS125 flashes yellow in search then goes to flashing green every 4 seconds indicating it obtained a fix and recognizing the NG converter.
At this time the converter solid green goes to a flash sequence of 1 green flash, then a second green flash about 2 seconds followed by 2 very rapid green flashes. No fix is indicated on the plotter and the plotter shows no satellite fixes on the gps status screen. I have just replaced the CR2032 battery in the RS125.
All Raymarine documentation states this should work but it doesn’t and I can’t find anything on this particular NG flash sequence. I’m thinking to cut the cables and wire the antenna direct to the output but I hate when I can’t solve a problem so I’m reaching out for any ideas before the wire cutters are deployed.