In the new translation dialog there are some checks to be done which do not seem to work:

• When the article exists in the target Wikipedia. Note that the title may or may not be different. This error is not about the article title but about an equivalent article (according to Wikidata) to already exist.
• When the above is not true, but there is another article with that name. this should be shown if the user writes an explicit article title, but also when the user does not write anything and the source title is going to be used as target title.