Hi @DStone323 ,
I made a sample for you. You can check your app or provide more detailed information, such as your formulas and running results.
Create an app, and add three dropdowns to select group, plan, bucket.

Group1:
Office365Groups.ListOwnedGroups().value

Plan1:
Planner.ListGroupPlans(Group1.Selected.id).value

Bucket1:
Planner.ListBuckets(Plan1.Selected.id).value

Copy the three dropdowns above, and add button and set the following formula.
Planner.CreateTaskV4(Group1.Selected.id,Plan1.Selected.id,1,{bucketId:Bucket1.Selected.id});
Planner.CreateTaskV4(Group2.Selected.id,Plan2.Selected.id,1,{bucketId:Bucket2.Selected.id})

Select from dropdowns and click the button.

The result of the run is as follows.


Best Regards,
Wearsky