Failed to parse nonce as string

I’m seeing the following error in the Logs:
Failed to parse nonce as string
What does it mean? Google is failing me.

A definitive answer would require additional information, in particular, the exact authorization endpoint request that triggers that error.

Having said that you can reproduce the error in question if you include more than one nonce parameter in the authorization request performed to /authorize so you should review how your client application is performing that request.