AirPods no longer listed as a device on Find My iPhone

I recently got back from a trip and while unpacking I noticed my AirPods are not in their case. I went to the "Find My" app to see where they were the last time I had them connected, but they are not listed as a device. I've had "Find My iPhone" enabled for a while and they have always been shown under my devices, until now. I contacted Apple and they said that my AirPods should automatically be on the "Find My" app if I have connected them to my iPhone (which I have MANY times) and they are under the same Apple ID (which they are). So sadly, that wasn't much help :(

Any suggestions on how to get them listed as a device again? Again, I do have the charging case, I'm missing both the AirPods.