I think a lot about the scene with the boys trying to find the book in Case of the Dandelion Shrine, but I don't think I'd thought enough about when and where it takes place.
The boys get more and more disconnected from each other during the first few episodes but they are in the office away from Crystal's gaze for about 90 seconds before they start acting like this:
"You'll rip your arm clean off. Stop that now! ...I'm not as quick as you, but I am here to help. Honestly, Edwin, can't you tell me what really happened with the Cat King?"
"Right. Fine, then. How about this? Take a deep breath. And put your big brain to work, 'cause the answer's gotta be in there somewhere."
Like... they are Home and In Private for barely a minute before they relax into this dynamic, which is, notably, not the one they show in canon-era, most of the time - but it is the one that we're shown in the pilot is 'normal' for them.
The Charles who coaxes Edwin to share, stops his self-harm, guides him through breathing, praises him to calm him, that's not the Charles that shows up in front of Crystal (or even Niko). But it absolutely is the Charles who bounces around Edwin trying to coax him into playing - er, boxing - to nudge him into new things and to keep him safe and to have fun with him, the Charles who specifically selects a "gentleman's sport" to try to suit Edwin's tastes and then gives puppy eyes knowing full well Edwin couldn't deny them even if he'd chosen MMA.
The Edwin who follows Charles's guidance, lets himself be soothed, follows care-related orders promptly with only a minimum of brattiness, that's not the one lashing out and bristling his authority in Port Townsend. But it absolutely is the one who caves to bouncing-Charles's puppy-dog eyes instantaneously, who barely bonks Charles with his fist and then raises his eyebrows proudly anticipating Charles's praise for the bonk, the one who lets Charles shove him to knock him from freeze into flight and throw him all the way over a desk because if Charles is doing it that means it's to keep him safe.
And, incidentally, it's also a lot closer to how they are in Hell. Even in literal Hell they're closer to their norm because at least they're in private.
We also see little bits of it every other time they snatch a few moments of privacy, even though it's way toned down outside of Home; Charles spilling about kissing like five minutes after doing it, Edwin trying to come out and then doing so, "best person I know", "...what are you worried about, then?", etcetera.
They want to tell each other every thought they have the moment they have it; they want to take care of each other. They're just only capable of it when they're alone and safe and have time away from judging eyes.
And, like... when we recognize that this is their norm, so much so that they go back into it the moment they are in their Space, like, quite honestly, no fucking wonder they're both crashing out the whole time they're in Port Townsend!
Edwin's clearly been outsourcing a lot of his emotional regulation to Charles, which means with Charles unable to provide it, he's got nothing to keep him stable.
Meanwhile, Charles is dependent on that role for his own emotional regulation, so he freaks out when he can't do it. (This is very clearly established: "What good am I even doing? I couldn't stop Devlin from murdering his family over and over. I can't stop Crystal from hurting. I can't stop whatever is going on with you." He explicitly crashes out because he is unable to "keep the spirits up". There are other factors, absolutely - but it's stated pretty clearly that if he were able to successfully fill his normal role right now, he'd be able to manage the other shit.)
We love a pair of deeply codependent lads whose codependency is backfiring because they can't go home and metaphorically cuddle on their tiny tiny loveseat <3