Low voltage lighting issue

i have about 2 dozen post lights with halogen bulbs around my deck, installed about 15 years ago. Most do not light up anymore. For awhile they wold turn on if I jiggles the bulb. Decided to begin replacing them. I bought 4 led low voltage fixtures to try out, and the first one I wired in, however, the lights blinks every 3-5 seconded and doesn’t stay on. I didn’t replace the lead that runs around the entire deck, I clipped the new light into the lead with the quick connect wire that punctures the lead wire. Below is the light I am using (from Lowe’s), really like them just don’t know why it doesn’t work. I guess I could try replacing another light and see what happens.
Portfolio 2-Watt Specialty textured bronze Low Voltage LED Post Deck Light