Replacement AirPod flashes orange, won't turn white even after holding the setup button

I lost my left AirPod and bought a replacement. When I put them both in the case it flashes orange. Holding the setup button (I've tried for past 60 seconds) does nothing. When I put the new AirPod in the case alone, it would change to flash white and I could connect the single AirPod to my phone but it registered as an entirely new set (Devin's AirPods #3) even though this should register as Devin's AirPods #2). I already went into my device and said "forget this device" for my original two AirPods. Help?