Note – each individual Weaver Xtreme Plus License key works for only a single unique URL. Subdomains are different URLs, so that dev.example.com is different that example.com and would need its own license for auto-updating. The terms of the license do allow you to use Weaver Xtreme Plus on a dev site by downloading the .zip from your license management page on shop.weavertheme.com, and then manually installing it on the dev site.
In this case, it seems that the license was activated for the dev site and not the main site.