Well, the yoyo is can be unresponsive for many reasons.
It could have a wide gap (probably)
It could have a less responsive response type
That’s what I can guess since you seem to be a beginner.
You have to bind every time you want the yoyo back up to your hand. If its not going back up to your hand then you are either doing something wrong or the response is worn out.( Its probably the way you are doing it).
To bind, let me put it simply;
If you are going from trapeze, cross the two sides and (pretty much) let the loop go int the gap. I dont suggest this way at all.
You know the frontal trapeze? It is when the loop is around your throw hand but is farthest away from you. From that cross the loop and the string from your throw hand. Move the loop towards the gap and have it snag in there. It is suppose to snag, but when you throw it again, it should come out smoothly.
Its hard to explain in words just watch the video a couple of times and practice. I hope someone clears this up for you.
Hope I helped!