The last 2 releases were not transferred to your maven repo. Can someone tell me why these versions are not available? I did not receive any message after the upload and the files can be downloaded, but the addon is not available in your maven repo.
It is very important to submit the supported Vaadin version information as well as the correct licenses. If everything is submitted correctly, the files will be released in the maven repository.
However it is hard to find out what the problem really is, because there is no message after uploading the version (as a zip file).