Minor issue, easy workaround:
In the editor window, the context sensitive menu offers a number of Writing Tools, one of which is Translate To Another Language. All the writing tools launch to an appropriate site, except the translation option which is launching the Dictionary.com site.
This is Scrivener for Windows v3. However, it is the same behaviour from the older Scrivener v 18.104.22.168 version. So it is either working as expected , or a carry-over bug. Thanks.