OK, at least this is a step in the right direction. Chrome allows me to 'pin' bookmarks, so that any time Chrome is opened, they open automatically (see image). What was happening before was that all tabs would pick one of the bookmarks at random instead of opening to the correct forum. I would then have to switch to each tab and manually go to the appropriate page. I would have to allow a couple seconds between tabs - it seemed to have something to do with the login process.
Now they all go to the appropriate forum, but I'm not logged in on every tab. It's not as big a deal as before, since now I can simply refresh, but it would really be nice if this issue could be resolved.