Recently had a P0455 CEL code appear which is, apparently, a large evap leak. A little surprised by this, but have narrowed down two possible causes and only one of which would be of my own doing

In the past I have routinely siphoned gas from my vehicles to fill the lawn mower gas can and in fact attempted- unsuccessfully- to do this from my truck the day before the code appeared. But it did not appear that day despite a 20 mile highway drive. Is there a possibility I screwed up some "easy fuel" seal or interface? Nothing was obvious damaged and externally all looks well. Topped up the tank today after work and found no issues with the function. Have not reset the code yet as I don't believe inserting a few feet of soft vinyl tubing should have caused any damage.