I just found a solution to an issue that I’ve noticed and tried to resolve through the forums and wanted to pass it along so it could be communicated as a sticky post or something like that so that it helps others.
When you create a featured image portfolio gallery by uploading multiple images to the featured image of a portfolio post and selecting Gallery as the Media Type in the portfolio item setting section you get a slider in the post featured image area, which is pretty cool.
The problem comes in when you try to add another image to that same gallery. If you add another image, it takes over as the Featured Image but then does not appear in the gallery. I thought this was really strange and is definitely a glitch in the system. I don’t believe it’s supposed to work this way. What you have to do if you want to have the image appear as the featured image and also appear in the gallery is to upload it twice and then choose one of those as the featured image. That way, it appears as the featured image and also in the gallery itself. Strange glitch but glad I found a workaround that I hope will help others too.