The various OpenPGP keyserver synchronize, but that takes some time. If you know which keyserver will be queried, you can directly upload your key there.
I did:
gpg --keyserver hkp://pool.sks-keyservers.net --recv-keys EE539F98
gpg --keyserver hkp://keyserver.ubuntu.com --send-keys EE539F98
and now your key can successfully be found on Ubuntu’s keyserver, without having to wait until it automatically synchronized.
Actually I ran the recv-command multiple times to find a keyserver in their pool which already had your key.