Unable to cast Ice Nova of Frostbolts during Lavianga's Spirit

Hello I am unable to continue casting Ice Nova of Frostbolts during Lavianga's Spirit mana flask duration. If I cast the unique mana flask while I am holding the frostbolts hotkey the attack stops casting until the mana pot is done or mana is full. If I cast the flask and then attempt to start attacking with the skill it casts the frostbolt attack more slowly and my additional projectile frostbolts do not spawn. Once the pot is done the attack goes back to full speed and the additional projectiles start spawning again.

I have attached a video detailing the issue as my description maybe confusing. As you can see from the video my ball projectiles do not spawn and the attack is half speed until the flask finishes. In the second half of the video I cast the flask while I am in the middle of attacking and the attack stops during the effect but my attack animation continues at the normal speed.

Video Clip: https://youtu.be/iLP7iQ88f6c

Link to my build: https://pobb.in/GPKcL8hQ61di

Thank you for this information! Why does the ice nova of frostbolts stop casting in the second half of the video? Is that working as intended? It seems like the ability is not casting but the animations continues.Thank you for this information! Why does the ice nova of frostbolts stop casting in the second half of the video? Is that working as intended? It seems like the ability is not casting but the animations continues.

I have noticed that when the mana potion is active and I have an ice nova echoing away from me, the nova will re-trigger when I press my ice nova button instead of trigger on my cursor.