What is the exact version including hotfix? I am asking since there was a bug fixed which fits the description in hotfix no.10.0.6:
Pages - 404 error for pages with multiple wildcard aliases If a page had multiple aliases with wildcards in the URL path and the aliases had at least one wildcard in common (for example '/News/{number}' and '/News/{number}/{type}'), the system returned a 404 Page Not Found error when the page was requested through the more specific alias.
I would recommend applying the latest hotfix if not used already.