[Peanuts]

You sound like you have the tensioner fully extended - which is correct

You then screw in the tensioner cap (without the washer) until you feel it tighten against the tensioner.

The distance from under the cap head to the cylinder has to be 6 to 11mm. If you have 5mm then the chain and tensioner rail ought to be replaced.

That sticky tensioner will have caused your rattle, similar problem with the enduro bikes - that is cured by using a Dirt Tricks tensioner,