Q: why can't they find the problem??? on 2010 Honda Insight

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
2010 honda insight 8045 miles on the odometer
check engine light on.
dealer repaired leak coming from evaporation system and replaced valve. system reset.
next day, check engine light on,
same defect shown.system reset, next day, check light is back on, going back tomorrow monday
(1) Answer
(1) Comments
no number' just check emission system.

but they did get it fixed on the 4 try.
i got spidered. the line to the fuel canister had a web sack in it.