First question: which version have you upgraded from ?
The real issue is not so much the wrong host (you probably have the wrong host in your main wiki descriptor, take a look at https://myhost/bin/view/XWiki/XWikiServerXwiki page) but the fact that you have absolute URLs instead of the expected relative ones (as in /bin/view/Dashboard/).
Might be related to some short URL setup you have since I see your URLs don’t contain the webapp path (/xwiki/ by default). Could you indicate all the URL related configuration you have made.