Yes; I had to read it twice.
All the online chats made a lot more sense once I knew who everyone was IRL. They were just tedious/hard to follow before that. I was actually intending just to skip them on my second read through. Probably you were meant to be trying to work out who each person was but I (probably stupidly!) didn't realise that we would end up "meeting" all of the forum characters.
I also read on Kindle and first read through the text chat transcripts, which ruins the order, the second time I used the image versions and realised that it was meant to represent which chats were happening in real time, who was swapping between multiple windows etc.
It's a frustrating book because I feel like you have to have spoilers in order to make sense of the chat parts. It all makes sense once
If I was going to give advice to anyone reading it I'd say skip the chats on the first read through, except when Robin or Strike is meant to be reading them. OR - consciously try and figure out who of the IRL characters is each chat name, and stick to the picture format if reading on kindle.
I don't know if this is because I have spent time on fan forums in real life so I'm quite used to the concept of getting to know regulars without necessarily linking them with any real person, maybe that's why I didn't twig that's what I was meant to do in the story.