Guild Wars 2

I apologize if this has already been asked but it is possible to have two stat stacking sigils at the same time?

example:

Superior sigil of life ( + HP)
superior sigil of corruption ( + CD)

I ask this because i have both right now and only 1 seems to work at a time, usually the one in my main hand slot. Theres been quite a few bugs with engineers as from what ive been told (only been playing a month), is this to do with engineers or is it just not possible to have two at the same time? Could it also been 1 stacks first and then the other begins?

TY in advance for any help.

nope, you can only have 1 on kill stacking effect at a time and it will override any new ones while active.

Also main hand sigils happen first so your mainhand one will always be the stack you get.