Hello,
According to Maelstorm skill description it should surround the character and moves with him. However from time to time it doesn’t work this way, i.e. once activated Maelstorm can sometimes, if follow the skill animation, move away from your character. It happens to me in different locations with no specific conditions at the first glance:
and one more
If my observations are correct in some cases it happens when Maelstorm life time is running out and character is moving at this moment.
Below ypu can find screenshot with Maelstorm skills tree:
Best regards,
Strannik