There’s a lot of factors that’s in play here,. The most well known is the quality of your account. If you are following and unfollowing and your accounts looks spammy then users well not visit the link you are promoting.
Also, May i ask why you are using a watermark instead of linking the landing page in your bio? If it’s an aff link then you can use this method
It’s pretty hard to type website address from instagram app to browser on mobile. That’s why you will be lucky if you will have few clicks. Don’t think that it’s good idea. Better put link in bio. Also if you want use watermark, better watermark some call-to-action.