This fixed my 2020 Ram1500 fuel fill problem (so far). I bought the truck with 30K miles on it almost 2 years ago and it acted up on filling a couple of times in the past but not too bad. It seemed to me that something was obstructing the flow of gas sometimes. Fuel would actually be at the level of the top of fill tube at times (btw, it is a capless neck). I believe it is the roll over valve in the top of the tank that causes the problem. Anyway, about 6 weeks ago it got ridiculous!!! 20 minutes to try and trickle in $20 worth of gas and at multiple different gas stations. I gave up on filling the tank! So, here's what I did. I saw a video online with some guy that had a seriously clogged fuel vapor filter...I decided to check mine and after taking it down and apart, it was super clean and not fuel wet. Before I put it back together, I thought it would be a good idea to blow back thru the hose into the tank to make sure it's not stopped up. Blew in, all I did was pressurize the tank and the exhaust came right back out of the hose. That leads me to believe that did not cure my problem. After putting that back together, I decided I wanted to blow into the tank from the filler neck to open that check valve but how?... Since my garage is a cluster fluck of stuff laying around right now, I saw an old toilet flapper to use as a seal and short piece of 3/4 pvc pipe to blow into. I cut a cross slit in the top of the flapper and shoved the pipe thru it (see attached pics, if I have to do it again, I will use 1/2 pipe to get thru the secondary flap in the tank). ANYWAY, I stuck it in the filler neck, and the seal worked great. I blew and it seemed like there was a lot of restriction that eased up soon. I thought it might just be my imagination but finished up and went straight to the gas station. I fully expected no change, but Viola! Filled it up!! I was ecstatic! And I just filled up again today, no problem! I know this post may sound crazy, but I was an auto mechanic for 25 years when I wore a different hat, so I know how things work. For those having serious gas fill issues, I think the problem is likely the roll over float or flap or whatever it's called is getting stuck almost completely closed and need to be pushed open. Apparently, the weight of the fuel going in isn't enough to open it, pressure needs to be applied. I hope this helps someone out there! Thanks, and God Bless, Sean