Hello,
I have found a newer bug with Preservation Evoker as of recent with 11.0 that can happen when you use Emerald Communion.
it does not happen 100% of the time but when it does the animation that emerald communion does never goes away and for the rest of whatever instance you are in you are permanently stuck with a green particle animation at your feet.
I think the animations really cool but it would also be really cool to be able to see swirlies on the ground beneath me.
I found it primarily starts the animation backup whenever I use hover but it can just randomly happen anytime throughout the key/raid as well as stop but always persists through death and only stops after having left the instance.
I found someone is also reporting this issue at US server, please refer to below link.