$fotorama not loading consistantly

I know this has been asked before, but I haven’t been able to find a solution. I’m using the latest version of Magento 2 with the Porto theme. Occasionally things will load ok (especially in Firefox), but $fotorama doesn’t load consistently, and as a result, images don’t look right.

What I’ve tried:

• disabling lazyload for product images
• disabling the old media gallery
• running the resize command for all images
• removing gallery from my attribute sets and only leaving image_gallery
• Clearing all caches (server and browser)
• reindexing
• calling the fotorama library in requirejs-config.js like this

var config = {
    paths: {
        'fotorama/fotorama': 'fotorama/fotorama',
    },
    shim: {
        'fotorama/fotorama': {
            deps: ['jquery']
        },
    }
}