If you have any issues with the media gallery in a blog post using SmartWave Porto Theme, please follow the steps below.
First of all, if there are no blog post media gallery settings in the Magento 2 admin panel, please make sure that you use the latest version of blog extension.
Then create a new file in your theme directory:
and add this code into it.
You need to do this as by default Magefan Blog Extension use FancyBox 3 for media gallery, and Porto theme uses FancyBox 2 and this new template will run media gallery using FancyBox 2.
If you need to change Fancybox settings please edit gallery.phtml file using FancyBox documentation.