How to prevent stringy, larfy buds?

Hello everyone and thanks for reading.
I have been consistently able to grow nice thick, chunky (resinous too) buds. All conditions and strain have stayed consistent, but my last harvest ended with lanky, stringy herb. I actually couldn't really tell until I got my scissors on them. Does any one know steps to take in avoiding this for my next grow?

Were your growing conditions identical between the two grows? If so I would think you're seeing genetic differences.

The problem room was slightly hotter and drier. The genetics were the same. I have only recntly learned that 75 is more desireable than 82. The temp was sometimes 85-86 at the top bud in the hottest part of the room. This has not been a problem for me until now.(no one has ever complained about the quality and most would choose mine over others) My current situation is much closer to 75, and I am very excited to see how they turn out next month.
Thanks for the reply!