As far as I know Autonumbers won't necessarily be created in sequence. They are merely a way to have unique numbers in your database. Use a sorting attribute like an integer or a datetime if you want to make sure you have a sequence.
I hope you are using Auto Number for your ticket ID attribute.
In that case, for example if you created an object for ticket but you are not saving in to the database, then also Auto numbering will happen.
When you create ticket object for second time, the number will be 2 for ticket id instead of 1 even though you did not saved the first object in to the database.
Because of this you are getting incorrect sequence. Use integer datatype for ticket ID attribute
The above is my create object microflow. This opens a form into which I enter the details, then I call the below microflow:
Am I doing this right?