The flood likes are working as expected. The bulb...

The flood likes are working as expected. The bulbs for the grass path and area lights are not working as expected. They periodically turn off and then back on. About half of them act in this fashion and they turn back on in a relatively predictable time frame of about 12 to 15 seconds. I have checked all the connections and I can still not figure out why this is happening. Would appreciate any assistance you can provide on how to resolve. We are purchased another set from Costco to install in our Beach House and I'm hoping that I do not have a similar problem. Look forward to your response.