bug about weapon swapping and spirit skills

I don't know if it's a bug or not but I believe it is.

Currently I'm running bloodmage with 2 CoC and elemental conflux, 2 CoC for mapping, 1 CoC and elemental conflux for bossing, and I also set second weapon set for bone offering and sigil of power.

The problem is because I don't have enough spirit on my second weapon set so I have to deactivate one of my CoC for second weapon set to use bone offering.

I set both of my CoC and elemental conflux only to the first weapon set, but everytime when I deactivate one of them and reactivate those spirit skills, their setting would be automatically changed back to both weapon skills. Which annoys me a lot beause I want to get everything prepared before entering boss room, other than changing my skills in front of boss(which also wastes my buff time).

I tried to set other skills like spark only to the first weapon set, and take the skill gem off the skill panel, then socket it back, then spark is still bind to first weapon set.

So I believe what happened to spirit skills should be a bug. I hope I described it clearly.