Check your fuses?
Make sure you have turned on the lights and are not just driving with daytime running lights.
Just got this car 3 months ago, 2018 CX-9 Grand Touring. I did swap the license plate bulb and that was it. On my way home tonight i got pulled over by the cops and they told me none of my lights on the back end of my vehicle work, but the break light does work.
You mention swapping bulb, are you saying that you swapped out the incandescent license plate bulb for LED?
It is possible for a bad led bulb to short and blow a fuse.
Dang it ok. Any idea what tail light bulb will work and won't blow the fuse
You said license light previously, now are mentioning the tail lights, what bulbs were replaced and exchanged by you? (scratch)
If it were me, I would put the original bulbs back in that you took out, and see if that fixes your problem.
Hopefully you just blew a fuse and not the Body Control Module. (gossip)
Is it the fuse in the car or under the hood?
Fixed it, replaced both license plate bulbs with new Philips LEDs and all the lights in the back end of my car work again at night.