Did you install and hook up the lights and wiring yourself?
Series wiring -- Hot wire connected only to one wire of one light fixture. Other wire of that light fixture connects only to ongoing line to next fixture. At next fixture line from previous fixture connects to one wire of fxture. Other wire of fixture goes to continuation to yet another fixture. Never done in household wiring for multiple light fixtures but may be found in some laboratory test equipment for light bulbs.
Parallel circuit -- Hot wire (black) connected to black fixture wire and also to black wire of cable continuing to next light. Neutral wire (white) connected to white fixture wire and also to white wire of cable continuing to next light, as separate bundle from black wires. Same at next fixture.
Note that a switch is connected in series with the light it controls (or in series with a group of parallel connected lights. With power feed cable with hot and neutral entering the box, the hot wire (black) is connected to one terminal on switch. Other terminal on switch connected to black wire of cable going to the light(s). In the switch box the white wires are connected to each other and not to the switch. (Different rules
for switch box with only one cable.)