Inapropriate loss of sigil stacks.
Just experienced this in PvE as well. I tried multiple ways to prevent losing the stacks on weapon swap, such as running the sigil on every weapon (which the wiki states can be done to prevent losing stacks), running it on only one weapon, swapping slots in the staff I had it in, swapping around between main and offhand on the other set, ect….. Pretty frustrating when you spend all that time and get up to 25 stacks and right before you hit 26 you need to weapon swap for whatever situation and they’re all gone. To me that is a bug, no other chargeable sigil has done this to me. Hope we can get some attention on this and get it fixed. it makes the sigil just as useless as it was before the sigil changes.
Here is a video of it happening:
http://youtu.be/NBKRkHdoJBQ