Gas syphoning out the vent/tank problems

Hey guys, been a LONG time since I've been on here, but need to get comfortable with my car again.

I had my car worked on a year or so ago, and had a couple issues when I last got it out, and hate to say it but it's been sitting in the garage for too long now.

Initially taking her out, I ran out of gas pretty quick, and died in town, next time I took it out, I went straight to the gas station. And at the pump, fuel just started spitting out the vent tube. Stopped pumping, and it kept going and spit out a few gallons right onto my exhaust...

Taking a look, the fuel tank and vent tube, it looks like the proper factory setup. I ran a camera into the fuel tank, and it seems like it's about half full or less (I'm also having weird gas issues like it's not making it to the carb, so kinda wondering if my fuel tank/car stance is making the fuel sit in the back of the tank.).

Anyway, the syphoning probkem... looking in the fuel filler tube, it looks like the vent section has a splash guard or something going down the length of the tube. I'm wondering if... Somehow, the vent is syphoning gas all the way down in the tank, because the filler tube vent section is gummed up maybe? Combined with the gas tank probably not laying as level as original, causing me to not be able to fill my gas tank up more than a few gallons...

Thoughts/ideas? Does this make sense? It doesn't seem like this is a common problem that I can find, and I can't for the life of me understand how it could be syphoning so much, with the vent tube being at the top of the filler tube