When I’m washing my hands and arms in ghusl, I allow the flowing water of the shower head to continuously run/pour over my hands and arms. I have normal short nails and no barriers on them but what I find is that my nails don’t retain the water on them even though I can physically see the water run over them continuously and that all parts of every nail has been washed completely and it is the same when I pass my hand over them. The water either just dries up immediately on my nails or slides/drips off. can you please confirm what is wajib on me in this case? iI the passing of flowing water over all parts of the nails of my hand sufficient eventhough the water does not remain on the nail?

It is sufficient if the water passes over it and washes it. Thus, you are fine if you know that has happened