Tail Lights

I'm new to this forum. I have 99 suburban that the tail lights don't come on. I have replaced all 6 bulbs, checked the fuses inside and under the hood and i can't find anything wrong. I start it and no lights when the automatic ones come on and when i turn the switch none come on.
the brake light which seems to be the middle light of the 3 on each side works, the blinkers also work and use the middle light of the 3.
Any ideas i'm lost :uhoh:

the plastic panel that the light bulbs plug into is bad.. replace cost at dealership is 39.95