Airpod Pros stuck on flashing white light, nothing changes that

Hello - desperately hoping someone can help

One of my airpods stopped working. Following the apple instructions online I unpaired (selected "forget this device" in bluetooth) in order to reset. However, they are stuck now on flashing white light and nothing I do changes this.

If I take out the left airpod, the light briefly goes orange then goes off.

If I put it back in it goes back to flashing white light

If I take out the right airpod, the light continues to flash white

When I close the case, the light just goes out.

I have tried gently cleaning the contacts inside the case with a clean earbud. I've tried cleaning the contacts on the airpods themselves ditto.

I've tried restarting the phone. I've tried pressing the button on the back of the case but nothing changes no matter how long I hold it down for.

Any other suggestions? Thank you!