I am running my own 2 player server, and have been consistently running into the issue of chunks not loading after a certain point, all in a line. Unlike chunk errors that I am used to, this border is unpassable and also there is nothing rendered past it. I can only relogin to the server to load the chunks, put the problem is consistent meaning I have to log in and out of the server constantly while travelling any bit of distance. If I try to pass the border I get stuck and have to relogin to the server to resolve the issue.