Yep, that’s the one – the theme adds the portfolio option. Unfortunately, as a premium theme, and an impoverished developer, I can’t gain access to their code to work out the cause. They also don’t have a forum and the only support is for members.
Sooo, your best bet it to open a support ticket with them here… https://www.wpzoom.com/members/login.php?intent=tickets
I’d basically tell them what you told me – that the Portfolio menu option disappears when you activate this plugin. Explain you’ve contacted me but because I don’t have access to the theme source I can’t resolve it. However, if WPZoom what to get in touch with me to work on this together, I’m happy for them to do so. They can get hold of me here… https://artiss.co.uk/plugin-contact
It’s an odd one though. When you create a menu in WordPress you assign it a unique ID. As long as they don’t clash one plugin shouldn’t affect another. Bearing in mind I’m using an ID very specific to my plugin I can’t understand why this would therefore occur, so it’s quite an odd one.
Sorry I can’t be any more helpful at this stage.
David.