You didn’t give me much to go on. You should really talk to the prescriber about whether you are experiencing a side effect.
I do have one guess: Sometimes when a person gets serious about quitting smoking, the result is tremendous anxiety. You want to quit. But quitting makes you anxious. The anxiety makes you want to do go back to smoking for relief. That can feel like OCD.
If that’s what you think is happening, I strongly encourage you to add some talk therapy to your treatment for smoking cessation. Quitting smoking is hard! It is likely you need some more support while you do it.
I wish you well.