There were no patch notes that it now functions underwater…
So if you’re by water, you can go swimming, eat your stim, come back up and still have your magnetic aura.
I’m not saying it’s a good solution, just that it is a solution… kind of.
I’m also expressing my disappointment that the trait is defunct underwater still, but that’s a different issue (I’m assuming this is the case as I haven’t been in game yet).