Question regarding XC1DE affinity chart

So last night I completed the game for maybe the third time, aiming to be as thorough as I can without relying too much on guides. I was reviewing my affinity chart when I noticed that, in the top right of the affinity chart where it shows you a small image of the entire web, one of the five major area nodes (central bionis) was glowing faintly.

I can’t seem to find any info about this online, so I wanted to see if anyone can fill me in on what it means. My first guess is that it means either everyone is registered or every link is completely updated as far as it will go.

I’d be curios to hear other people’s approaches to filling out the affinity chart as well, given how easy it can be to miss people.

Thanks in advance!