Firebase functions: Error SignatureDoesNotMatch

Hi, there!

I'm facing the same problem but I've already removed the content type while creating the signed URL.
The interesting fact is that this problem only happens suddenly a few days after the signed URL is created..

The code I'm following is the one below:
https://github.com/firebase/functions-samples/blob/master/generate-thumbnail/functions/index.js

Ps.: I have already followed the tips in the link below but the problem remains:
https://github.com/GoogleCloudPlatform/google-cloud-node/issues/1976

Thanks in advance!