You probably purchase a so-called “active”, battery powered, capactive-type stylus.
These types of commonplace capacitive stylii have a fine tip/ballpoint-like tip/nib, that uses a tiny battery to send small electrical signals to a fine point tipped stylus that mimics an actual finger touch.
No Bluetooth connection is necessary with these types of stylii.
They work just like ANY commonplace, purchase anywhere, cheap capacitive aluminium barreled stylus.
All of these types of types of “active, battery powered, capacitive stylii suffer from varying degrees of line wobble when drawing angular lines. Some of these types of stylii are worse than others.
Newer versions of these types of “active”, battery powered stylii may actually allow you to place your palm or the side of your hand down on the iPad's screen, now, as you write or draw.
If your particular stylus does not allow this ability, there are inexpensive special non-body electrical conducting, lycra- material based drawing/writing gloves for touch screen devices that allow you to lay the palm/side of your hand on capacitive touch screen tablet that isolates your actual hand from the tablet's screen so it will not send any electrical signals to the tablet’s screen and not make false or accidental touches while using an iPad or other capacitive touch screen device while writing or drawing.
Something like this found on Amazon.
https://www.amazon.com/Professional-Anti-fouling-Drawing-Tablet-Graphic-Right-Ha nd-Left-Hand/dp/B017R8M2JY/ref=sr_1_1_sspa?ie=UTF8&qid=1543548123&sr=8-1-spons&k eywords=lycra+drawing+gloves&psc=1
Many more makers of these types of gloves found on Amazon and in different hand sizes and colors, as well!
Best of Luck to You!