This is you regex
^.*Aurix_MC-ISAR[^mak]\/port.*
Its breakdown for your string says that
^ #Start the string
  .* #Consume everything till next string is found
  Aurix_MC-ISAR #Find this string literally
  [^mak] #Match anything except m, a or k (In your string Aurix_MC-ISAR, what follows just after it is \ which is neither m, a or k. So successful match)
  \/ #Now there is no / in your string further. So it fails here
port.* #Whatever here it won't match as it already failed
See here
NOTE :- From what I understand you are using \ in your input. So for escaping \, you need to use \\ instead of \/ which is escaping /. Though it will not make any difference in your output because there is not any extra \ after Aurix_MC-ISAR\