[2019] Has the ability to stall adrenaline been nerfed?

I've just come back to RS after a 6 month break and had a go at some bossing. I notice that there has been a change to combat in the sense that when your adrenaline begins to drop, regenerate activates automatically to restore health, and I've been trying to activate abilities to stall the bar but it doesn't seem to be working like it used to.

The movement abilities (surge, escape) activate immediately, but the defensive abilities dont' seem to, leadingh me to losing most of the built up adrenaline. Has there be some kind of update which has changed the capacity to do this, or is there a setting I can change to disable the automatic activation of regeneration as I feel this may be part of the issue?