Low voltage LEDs fluctuate from full to half to off and repeat

I purchased and installed 100′ of 16/2 wire and eight lamps (LED Lawn Light 12W 2800K AC/ DC 12V) and Malibu’s 200 Watt Low Voltage Transformer. 96 watts of lamps, I was told, would be perfect for a 200 watt transformer.

I carefully installed the system checking each item as I completed it. The transformer was placed 18 inches from the outdoor ground fault plug with the nearby light sensor. The first light was installed 22′ from the transformer with connectors to each of the wires from the lamp. Each time I connected another lamp, I would double check that each connection was successful by turning on the transformer. I then buried the wire 2 1/2 to 3" beneath the mulch after safely taping each connector. The last lamp was attached 18" from the end of the cable.

Testing each connection showed a prefect system installation. However, when the sun set and the system came on automatically, lights began to blink, not in unison, but alternately at random. Each light had full brightness for about 45 seconds, then go to half for about 20 seconds and then turn off for about a minute before it would turn on again with full force to repeat the pattern.

As time has continued, I find the connectors of the cable and the lamps disconnect (lousy connectors, I think, but Amazon reviewers say they are best) and at this time only one lamp is lite. Even with the one lamp it jumps back and forth from full to half every two minutes or so but unlike before, it does not turn off. I now have a full system that is unusable.

Can you help in any way with advise or whatever? Thank you very much.