Seems like it might be packet loss. Here's my screenshot of wireshark output vs the screenshot of the guide's wireshark output. Sorry the quality isn't great, I tried an imgur link but it was even worse
DeepinScreenshot_20200118123533.jpg
Edit: Is there anything I can do to help with packet loss, if that is the problem here? Router settings etc? I'm grasping in the dark here
[You must be logged in to view images. Log in or Register.]
Edit#2: After some googling it seems that Manjaro Linux comes packaged with everything that the "sudo apt-get install build-essential" command would install.