is Sigrid bug on venom 9?

[potent orchid]

id: 1608636470705099776
i was traying to beat venom 9 in Auto, but i realizes my Sigrid all the fight is hitting boss, but when is on 30-40% she start to shoot her max skill to the sphere, but keep shooting basic and 1st skill to boss, sometimes hit both cuz the boss have the heal-reduction debuff, is this a bug ? or is part of a hide mechanic to make auto fight hard??

[fallow crater]

Dear Traveller, Thank you for contacting us we're so glad to serve you.
Regarding Sigrid's issue, we apologize for any inconvenience caused. Kindly note that we've reported the issue to the relevant team and get back to you as soon as possible.