Dutch Flat Mates (Sandwich Sums): Vortex: A Tasty Sudoku Treat!

Today's Puzzle:

Returning to Flinty's Dutch Flat Mate ruleset with a cracker, mmm, a sandwich of a puzzle!

Link to Play Along:

Dutch Flat Mates (Sandwich Sums) by Flinty https://tinyurl.com/SudokuSleuthDutchFlatMateSandw

Rules:

Normal Sudoku Rules Apply

5's live in Dutch Flats All 5's in the grid must strictly have EITHER; a '1' directly above it AND/OR a '9' directly below it. It may have both, but it doesn't need both.

Sandwich Sums Numbers on the outside give the sum of the digits between 1 and 9 in that column or row.