Need information about possible evap issue

So.........started out with check engine light coming on. Truck drove fine with no issues. Got checked. P0441 code(evap emission system incorrect purge flow).When I lifted the hood I found that the hose that has the evap service port on it( two small hoses actually) were disconnected so I reconnected them, reset engine check light by taking battery cable off and putting back on, and problem solved. First time driving it after the fix and Now I have new problem. When coming to a stop or slowing down without foot on accelerator, the truck cuts off. Having to put in park, turn key to off and recrank every time. Could this have something to do with the hoses being off? As I said before the truck drive fine with no issues even with the engine light on for the short time it was until I fixed hoses. Side note when I press the gas pedal the interior dash lights get brighter and the battery gauge move just a hair. I have rechecked battery hookups since I reset engine light and all seems ok so I’m just confused at this point. Any advice at all much appreciated!