You should add in your collection item a link or a link block element. (add elements in the top left menu).
Once it’s done you select that element and on the top right menu (the gear “element settings” the second of the menu) you go for Link settings.
There you can choose to use a “link” field in the collection you are currently in or as I guess it’s your case now you can select the second option of the link settings menu “collection page” and then you choose “Current collection name”.
In case you can’t find those options or it doesn’t solve your issue please come back without forgetting to include a shareable link so we can take a look in the project to understand better.