Embedded widgets occasionally not loading CSS

I have embedded Piwik widgets onto a site that are being pulled in through an iframe. For the most part, the widgets are displaying correctly and everything is sitting comfy.

On a reasonably rare occasion the embedded widgets load in with a lack of styling, see the following image: https://s3-eu-west-1.amazonaws.com/piwik-image/piwik-css-missing.png As soon as I open up the developer tools, reload the page to view the network tab, the CSS loads in.

Any ideas why this is happening? Or where to start digging? I’ve experienced the issue on Chrome, Mac OS X 10.8.

Thanks in advance,

Update: I’m also experiencing the issue within the Piwik admin area. Therefore, I’m not thinking it is widget related but something with the Piwik install. I haven’t modified any of the Piwik souce. Has anyone experienced anything similar?

Picture of the loss of styles:

See Troubleshooting - Analytics Platform - Matomo