Hi,
No no, the processing of content plugins in descriptions is there since almost the first version of HikaShop and it works for everyone else. So it doesn't come form HikaShop.
I think that your problem comes from your content plugin which refuses to load when not on a joomla article page. This happens sometimes based on how the plugin was coded.
If you really want to use that plugin, you should ask your plugin provider's support for help on that one.
Otherwise, you should try with another content plugin. Around 80% of content plugins should be compatible with products and categories descriptions.