I have three periods of Calc AB, one of them first thing in the morning. I had the same situation last year and that group was incredibly enthusiastic and ready to start the day. This year...not so much. Lots of tired faces and it takes a while to get them going. Plus, it's the smallest group, only 21 (compared to 25 and 28 in the others).
For the first semester (when it was only 20), they sat like this (the back tables seat 6, the front 7):
Conversations were limited, and performance was poor, scoring about 10% less than the other periods on our first benchmark. In general purpose assessments they were about 5-10% lower than the other classes as well. The table at the top left in particular did a lot of staring their paper, uninterested in finding assistance around them or even asking me.
It was clear things weren't working, so when January rolled around (and we gained 1 kid from another period), I forced them to do this:
It's a little cramped but it has made a world of difference. The low performing table is gone, and there is far more conversation happening when it's time for an assignment. When it came time for benchmark two, this class is now more in line with the others, off by a rounding error.
They always had access to each other, but forcing the issue and making them be more friendly has had the intended effect. Never be afraid to change it up when it's obvious something isn't working.