Low voltage transformer with 4 terminals

I have some low voltage landscaping lights with six fixtures each containing an 18w bulb. (This system was in the ground when I came to live here). I have two 12/2 wires coming into the transformer from the fixtures. I replaced the transformer today. It’s a Portfolio 200w from Lowe’s. The old transformer had one terminal that both wires from the fixtures fed into. The new transformer has two terminals. I hooked one 12/2 wire to one terminal and the other 12/2 to the other terminal. Lights work when set to constant ON. However, when set on dusk to dawn setting the lights don’t work. Could it be a bad photo sensor on the new transformer? Or, could using both terminals instead of one have anything to do with my problem?