Page not fully loading

[ep16]

I have WPT automated to run on a private instance in regular intervals. At a certain point, some of the pages I'm testing stopped reaching the end of their render. I thought it was likely an issue with my app, but I have not been able to recreate it.

Basically, from looking at the filmstrip, I see that the sidebar/header of my page loads, but the test completes prior to content being filled in. Has anyone else seen this? I don't think I have touched any configurations/settings that might have affected this.