AirPods case flashes orange and doesn’t charge

Flashing amber light indicates that you may need to set up your AirPods again.

From the Apple Support document, Charge your AirPods with charging case and learn about battery life.

When you connect your Wireless Charging Case to a charger, or place it on a Qi-certified charging mat, the status light will stay on for 8 seconds. If the light flashes white, your AirPods are ready to set up with one of your devices. If the light flashes amber, you might need to set up your AirPods again.

I had the same situation and managed to overcome it.

Symptoms:

• After Airpods got out of battery, it didn't reacted at all without any indication.
• When I connected it to charger, it indicated by amber blinking, but still didn't reacted to any of my actions (short-press to button, long-press)

The solution was to clean the lightning port with a needle (or something). Therefore, Airpods said to me that charging device detected, but they failed to charge properly.