AWS S3 Bucket name already exists

According to the AWS docs:

An Amazon S3 bucket name is globally unique, and the namespace is shared by all AWS accounts. This means that after a bucket is created, the name of that bucket cannot be used by another AWS account in any AWS Region until the bucket is deleted.

Someone else has already created a bucket with this name.

So, I finally solved my issue.

As I stated in the description of my question, my problem was not the formatting or the validity of the bucket name, the name was also unique and not used. Weirdly enough, I could not create the bucket when signed in using Chrome, but I succeeded doing it using Edge.

One note for the happy down-voters: maybe you can share some of your wisdom explaining the reason for down-voting, so we can all learn from it.