Internet browser displays a white page for some websites

As said in the title, a number of websites simply load as a blank white page when visited. I first assumed that the sites were down but I am able to access them from other devices (phones and computers).

I found this thread from a year ago and followed the steps, which fixed the problem for about 2 minutes and then reverted and continued not loading the pages.

It does it on Chrome, Firefox, and Edge. I've tried uninstalling and reinstalling Chrome to no avail. I've uninstalled all my extensions such as adblock and all the others. None of the extensions are too odd and I couldn't see any of them causing problems, I've had them for years as well. I tried manually assigning a DNS but that hasn't changed anything.

The sites don't have anything in common from what I can tell. The three main ones are Warhammer Community, a games store in rural Australia, and a group that sells misshapen vegetables for cheap. There may be others that do it but those are the main three that I've noticed.

I have recently (a little over 2 weeks ago) contacted my ISP and had them remove the CGNAT from my service so I could port forward to host a server. The issues started about a week after that, I'm unsure if that's related at all.