CSS not resolving because of https error

I installed this plugin to try and fix the website I am working on. Any secure pages I have the styling falls apart. I cannot link the site because the error is occurring on a checkout page (you need a product). However, here is the console log for the page.

Mixed Content: The page at ‘https://fitnesskitchenla.com/checkout/’ was loaded over HTTPS, but requested an insecure stylesheet ‘http://fitnesskitchenla.com/wp-content/uploads/wp-less/dt-the7/css/wc-dt-custom-8c37e4d4ce.css?ver=1.0.0’. This request has been blocked; the content must be served over HTTPS.
fitnesskitchenla.com/:1 Mixed Content: The page at ‘https://fitnesskitchenla.com/checkout/’ was loaded over HTTPS, but requested an insecure stylesheet ‘http://fitnesskitchenla.com/wp-content/uploads/wp-less/dt-the7/css/main-084f8d9d74.css?ver=1.0.0’. This request has been blocked; the content must be served over HTTPS.
fitnesskitchenla.com/:1 Mixed Content: The page at ‘https://fitnesskitchenla.com/checkout/’ was loaded over HTTPS, but requested an insecure stylesheet ‘http://fitnesskitchenla.com/wp-content/uploads/wp-less/dt-the7/css/custom-084f8d9d74.css?ver=1.0.0’. This request has been blocked; the content must be served over HTTPS.
fitnesskitchenla.com/:1 Mixed Content: The page at ‘https://fitnesskitchenla.com/checkout/’ was loaded over HTTPS, but requested an insecure stylesheet ‘http://fitnesskitchenla.com/wp-content/uploads/wp-less/dt-the7/css/media-084f8d9d74.css?ver=1.0.0’. This request has been blocked; the content must be served over HTTPS.
https://www.googletagmanager.com/gtm.js?id=GTM-PZ32Z8 Failed to load resource: the server responded with a status of 404 (OK)

I know the website url would be best but you cannot get it unless you put a product in your cart. I suggest using this url: http://fitnesskitchenla.com/meals/vip/
for the quickest product.

https://wordpress.org/plugins/ssl-insecure-content-fixer/