'03 Se/r: Trouble putting gas in it: Keeps tripping gas pump

[Buzzman]

Have an '03 Sentra Se/r, mostly driven by my son. While trying to fill it up, the gas pump keeps tripping as if the tank is already full.
Can literally only put in a few drops at a time before it trips. Takes forever to get anything in it.
No trouble codes at the moment.
Any ideas what it might be? A venting problem maybe?
I checked for recalls for possible rusting filler tubes, etc., but didn't see any.
Thanks in advance for your help.

[PapaSmurf2k3]

Is the nozzle going all the way in?

Maybe try and snake something down there to see if there is any sort of blockage...