Spark plug issues

I am having issues with finding the right spark plugs for my 2008 SeaDoo Wake 215. Last year I installed NGK DCPR8E‘s and had to screw off the caps so the coil would snap down on the plug. The plugs came with the caps on and they easily screwed off.

I just ordered the same plugs and the tips will not screw off. I twisted the entire electrode out of the plug trying to remove it.

Is there a specific type of spark plug I should be ordering?

I am at a loss

The caps should stay on