My LOTR spinner did that because the bottom of the spinner was widened from ball hits. File it flat or get a new spinner if that is your problem.

LTG : )

https://pinside.com/pinball/forum/topic/best-way-to-juice-spinners

With the spinner in the game, pitch the spinner with your fingers and push it away from the player gently. Give it a couple pushes and see if it changes it. No change? Give it a bit more force.

Pushing away from the player will bring the bottom of the spinner down. Pulling towards the player will bring the bottom of the spinner up.

Also double check the bracket is snug and the spinner arms are not getting caught on any screws.

What I do is disconnect the spinner from the switch below the play field and try to tweak it for a balanced spin. A couple of times I have had to adjust the spinner switch blade: Too much tension on the switch blade pulls on the spinner and slows it down. Too little tension and the blade will push the bottom of the spinner fore or aft.

In one case, I had to relocate the spinner switch on the bottom of the play field to get the proper rest position.