2016 – Embedded SharePoint Site Page Throwing Error for Promoted Links

I have been stumped on this for days. After migrating to 2016 from 2013, certain pages with promoted links (tiles) web parts broke. Accessing the page directly, there’s no issues; however, when you access the page through another website (as an embedded page), it’s broken. I tried toggling the “Server Render” in Miscellaneous. The items displayed fine that way as well.

The following error is displayed:
TypeError: Cannot read property ‘UseClientSideTheming’ of undefined
Example of Error

I’m quite the newbie when it comes to SharePoint. I inherited these pages, but digging through the code in SharePoint Designer, I see that it’s using the following to embed the page:

<WebPartPages:AllowFraming ID="AllowFraming1" runat="server" __WebPartId="<ID removed>"/>

Should it be set up differently? Could this be causing an issue somehow?

Any help would greatly be appreciated.