Other Fuel System Hoses Lines/piping, And Fittings problems of the 2011 Chevrolet Suburban

Engine light on-diagnosis p0455. Last 2yrs took to many repair shops. Replaced, gas cap, purge valve, canister valve, charcoal canister. Took to chevy. They replaced purge valve because they said other mechanics used non chevy parts. Engine light came back on. Chevy did smoke test and swore it was the fuel sensor cost $1200+. Engine light back on after a week. Another smoke test and now pressure test blew a small section of fuel tank where it now leaks. Chevy said the seal most likely not seated properly and I need a new fuel tank about $1000. But they can't guarantee this is the cause of the engine light. I can't afford another $1000 especially if this doesnt solve the problem. Already spent thousands fixing different parts. Vehicle gets about 12mpg and has in the past lost power while driving as if not enough fuel is getting through but that hasnt happened in some time. Wonder if anyone else having this p0455 issue?.

From 2017-present engine light is on and has code p0455. While driving down the road vehicle drives a bit rough and on at least 8 occasions it has lost power while driving down the road. Almost feels like its going to shut off. Three smoke tests were done, one at a Chevrolet dealer in 2017. So far auto repair shops have replaced 1)gas cap, 2) purge valve 4 times, 3) fuel sensor above fuel tank and we diy replaced carbon canister and vent valve solenoid. Still the problem persists.