Simplest option is that outlet F was also half-hot/half-switched and you were not aware of that, so breaking its tab (or isolating that red wire from the outlet and insulating it, if you don't want it half-switched) might fix your problem.
I would guess that you missed that in the original wiring, or it would work as expected.
Connections at B look like a switch loop out to the switch C, and the switched hot on red. The white wire in the switch loop should be re-marked with red or black tape at both ends to indicate that it is hot.
Actually, the blue connections at B look like you've got another half-switched at B, as well.