Twitter is not working correctly on my home internet?

[Dallas]

About a month ago out of no where my twitter started acting very slow on my IPhone (4s, newest software update) and I could not load/view a single picture. This includes profile pictures and pictures tweeted by other users. I can refresh my feed with no problem, but all the pictures show up as grey boxes and when I tap them to open them, the loading bar doesn't even budge. The moment I turn my WiFi off and use 3g Twitter works perfectly. This problem is also happening to all IPhones using my WiFi, not just mine.

I did not update/change anything to cause this problem. Before this problem I never had any WiFi or internet problems. Everything else is working fine over WiFi. For instance: Instagram pictures, Facebook pictures, and snap chat all work perfectly.

About a week ago I decided to log into Twitter on my PC (hard wired into router) for the first time. The same thing happens where I cannot view a single picture even if I try open open them directly by clicking of the link.

I am wondering if there is a port I need to open on my router to get this to work. Also I should add that there are no firmware updates for my router. I am using a Comtrend ADSL Bonded router.

Things already tried/Don't tell me to try:
-Reset router (multiple times)
-Update router firmware/software
-Delete and re install the Twitter app
-Make a new twitter account

Thank you in advance for reading this. I know it is very long, I just didn't want to leave out any facts.
Twitter does use an https address. But many other websites I use do too and they all work fine.