Hi,
Thank you for taking the time to leave a review. I’m wondering if you might not have “pretty permalinks” on the site where you are testing Gutenberg, I can reproduce this issue in that scenario.
To check that, go to Settings > Permalinks (in the admin menu on the left), by default this should be set as Plain, if that’s the case please try changing it to Post name, and see if things work better for you then.
If you have other plugins or themes other than a default Twenty Seventeen active, could you share what plugins and theme you are using as it may be a conflict there causing issues. In which case we would like to investigate that further.
