MacBook Pro displaying websites at incorrect aspect ratio
Recently, my MacBook Pro has been displaying websites at the wrong aspect ratio. I have attached 2 images illustrating what I mean. It does this on YouTube and Nexus Mods. I haven't noticed a change on any other websites. This is happening both on Google Chrome and Safari. I've looked at both website using developer tools but haven't been able to make the sites display as they did before. Any ideas on how to fix this? Thanks.
My MacBook Pro information:
MacOS High Sierra
Version 10.13.6
MacBook Pro (Retina, 15-inch, Mid 2015)
2.8 GHz Intel Core i7
16 GM 1600 MHz DDR3
Intel Iris Pro 1536 MB
MacBook Pro (Retina, 15-inch, Mid 2015), macOS High Sierra (10.13.6), null