New Router: Unable to download images from Instagram and WhatsApp

Question

We've set up a new router at home and most websites apart from images and videos on Instagram and WhatsApp don't load. As an example, I identified that I am unable to load this URL from my router:

https://instagram.fdel1-1.fna.fbcdn.net/vp/9068ec32350f293f6b8b42f342af9c6f/5CCF5EEC/t51.2885-15/sh0.08/e35/s640x640/15623582_1398870406790413_2246680131064037376_n.jpg?_nc_ht=instagram.fdel1-1.fna.fbcdn.net

The request fails with ERR_CONNECTION_TIMED_OUT (instagram.fdel1-1.fna.fbcdn.net took too long to respond.). Screenshot.

The rest of the resources (CSS, JS and HTML) from Instagram load and are rendered fine on the browser (and the phone app). Also, if I hit a different instagram server for the same resource, the image loads fine on this router. Example:

https://instagram.fotp1-1.fna.fbcdn.net/vp/9068ec32350f293f6b8b42f342af9c6f/5CCF5EEC/t51.2885-15/sh0.08/e35/s640x640/15623582_1398870406790413_2246680131064037376_n.jpg?_nc_ht=instagram.fdel1-1.fna.fbcdn.net

Facebook (and images/videos within it) load alright. YouTube videos and the rest of the web (that I have accessed) also work alright. So far, I've identified the issue only with Instagram and WhatsApp image/video content. As an example, I can load this URL from this router: https://scontent.fdel1-3.fna.fbcdn.net/v/t1.0-9/48384974_10216415697837895_1820001174888120320_o.jpg?_nc_cat=103&_nc_ht=scontent.fdel1-3.fna&oh=28819a292c7d21579d877b726b6c19eb&oe=5CA5D9B2

So, from what I can establish, I am unable to access instagram.fdel* subdomains from this new router.

I am able to load these images from

• A different router connected to the same network
• Directly with the LAN cable (the same LAN cable that connects this router)
• My mobile data network

However, if I connect my computer to this new router with a LAN cable, then this site doesn't load (in addition to it not working over the WiFi). I can reproduce this across multiple browsers and devices. So, it truly seems like an issue with this new router.

Other things I have tried:

• Restarted the router, also reset the router and setup again :)
• Changed the DNS from the default 8.8.8.8 to my ISP's DNS, as well as, some other custom ones (such as 1.1.1.1).
• Changed from ipv4 to ipv6 and back.

But, now I am out of ideas. Any thoughts on what might be off with the setup?