SooM and balanced stratagem

Hi everyone, SooM is consuming balanced stratagem without applying the accumulated bonus of 15% healing, nor making it possible to use it during the channeling of the skill to benefit others, such as enveloping mist and vivify.

I tried to check if the buff was working at least to increase SooM’s own healing but it doesn’t seem to be working, has anyone else noticed this?

I could be doing something wrong too so I would like to know your opinions