Help - Driver Bi-Xenon Headlight Problem

When I turned my headlight switch "ON", the driver side came on approxiamtely 5 second later or sometimes it never on. The dealer already replaced the ballast on the driver side early this year and it seemed the problem is not related to the ballast.
What would be the possible cause of this problem. My bulbs are OEM and they are new. I switcted the bulbs to test whether they were the problems and obviously, they were not.
What should I do? The warranty already expired. Any fixes?

Thanks.



