I have the same problem in my pool in Tobago. Pool lights turned off but I still get a tingle from the light surround (die cast alum) and the stainless steel handrail. I have installed an earth bond between the deck box, had rail and sub panel earth point. I have further installed an earth electrode approx 6m from the panel and bonded with 10mm cable.
Why should this happen?
Any solution will be appreciated.

I smell band-aids. You can read the US NEC code online by following the sticky when you click on "Electrical & Lighting" at the top left of this page.

The point is you need an equipotential grid within, I think 5' of the perimeter of the pool. That starts at the concrete.

Any metal like the hand rail, the light bezel, the pool skimmer, the water needs to be bonded. Where? That bolt on the pool pump that is begging for a ground to be attached to.

Everything else should follow in place with no additional ground rods etc. The pools EGE will take care of the ground requirements.

Thanks, I will delve deeper on my next visit to Tobago