When does roll20 archive the chat? What triggers it?

I have noticed that the day after a game, our chat has been partially archived, sometimes none of it, sometimes it hasn't even archived the chat from the previous week. I use the archive as much as possible to write our journal, but often the information just isn't there yet. Some of the actions/rolls will not show up in the chat in-game (because it doesn't scroll up that far) but it's also not in the archive (yet?). So I'm curious if there is a pattern I am not seeing. When, how often, or what triggers the archive, and can I do anything to make sure it gets archived as soon as possible?

For me, the game's chat log is archived immediately, so it's possible that there is a bug going on, or that your chat archive is corrupted in some way.  When you are reading the chat archive, are you doing it from outside the game? If you have a lot of stuff in the chat log, then it will be displayed over several pages: Are you using any browser extensions?  I know sometimes I'll get some weird chat stuff going on, then realize that my Stylus extension is hiding a bunch of stuff (especially error messages).  Other browser extensions like form fillers, translators, can also cause weird issues as well. I've started the habit of clearing my chat log after each session.  Before deleting the chat log, I open it up (outside of the game), click on 'Show on One Page', then right-click and save the whole thing as a 'Webpage, Complete'.  That way I can always go back to previous sessions if needed, but it prevents the chat log from getting corrupted over time.

I personally ran into this problem tonight, I go through the log after the session usually.  Very specifically my chat log for that session ends at the things done in the last session before it spun down and then spun up for the live session.  So my guess is that it does not add to the archive till the session is spun down.  

Thanks for the replies. I do not use any extensions or translators or anything like that. I know you're just trying to cover all the possibilities but yes of course I do realize it will be spread over several pages. I have tried looking at it as one page, and I've tried reversing the order in hopes that it would somehow load fresher content when I reverse the order again. For me there is normally a large gap between what the archive has actually recorded (or will display) and the little bit that remains visible in the in-game chat window. Sometimes I'm just missing an hour or two of info, and sometimes (like this week) it still had not archived the entire week before. When I wrote this post it was still missing about one and a half sessions, probably 5 hours or so of play. It's an interesting question whether I'm looking at it "outside the game." When I look at it, it is always the next day after the game, and the game has been exited and the browser closed all night. It is possible that I have a tab of the game open in the morning when I try to read the archive, but definitely for sure the game has been exited out the night before, has been scheduled for next week, and my browser has been closed overnight. I would think with the game closed by me (the GM) and sitting all night, it would have archived all of the chat and even if I had a tab of the game open the next day, I'm surprised that would somehow effect the archive. But maybe? I'll test it. I use two different computers and haven't noticed a difference (one a chromebook, one a PC using chrome browser) but I guess I'll pay more attention to the two and see if they're identical. That might offer come clues. Could one be corrupted? Maybe. I'll clear mine and see if it behaves any better, but this is not the first game in which I have noticed this behavior. It's just that I am becoming more and more dependent on the archive to refresh my memory as I write the journal, so the more I want and need to use it, the more I realize this is behavior that I don't understand and wish I could fix. I was hoping there was a simple answer, but I suppose not. I logged in to test some of these ideas and right now it shows no archive at all. It loads the normal buttons like Jarren screen-captured above, but nothing underneath no matter how long I wait or after refreshing the page. I'll post again once it is at least working a little bit.

12 hours after the live session ended, still do not see ANY of the live session in my chat archive.  

ok, well then at least it isn't just me

24 hours after the first person logged in and spun up the live session on the dot is now when the chat archive just backed up.  The new session is blank and the archive has everything that was there 1 hour ago.  

Ordinarily it's immediate*, like Jarren said. *The chat archive doesn't show new chat-texts instantly (live like the live-chat on VTT), but will show the Latest chat whenever you load/refresh the Chat Archive. So it sounds like there's a bug happening, from the above reports (?) Jarren said: For me, the game's chat log is archived immediately, so it's possible that there is a bug going on, or that your chat archive is corrupted in some way. 

My session went corrupt shortly after that update fwiw.  I have no idea what caused it as nothing new was installed in the API sandbox.