As far as i remember, you actual issue was on ID column not the Name Column

update your code like this:

{if Char.IsNumber(Row.ID)

{

Row.isvalid= true;

}

else

{

Row.isvalid= false;

}

}

1) you donot need an extra bool variable in it

2) Derivedname is not required so it been removed.

3) apply the conditional split on isvalid field only.

after applying this change, run the package and the share the results.