Hey! Glad I was able to help! I was kinda wondering if I was the only one with this problem.I think the reason we only had the problem on battery power is because laptop mode tools itself is set by default to run only when on battery power.
For power saving with laptop-mode-tools, you need to go through /etc/laptop-mode/conf.d as well as /etc/laptop-mode/laptop-mode.conf. You can also use the profiler but you still need to go through conf.d systematically. By default, anything considered potentially problematic is disabled so you need to enable a lot of stuff.