At the moment, it is very impossible to apply long formulas into the editor. Whether we are pasting or typing formulas, it always messes it up. Please, kindly revisit and test it yourselves, I am very much frustrated it had drained all my energy for the day, just for this challenge of accomplishing a very SIMPLE TASK of editing a formula. I dare you to try doing it yourselves and try if you can succeed in typing this formula in there:

IF(field("Priority") = "P0", 3, IF(field("Priority") = "P1", 2, IF(field("Priority") = "P2", 1, 0))) + IF(field("Due date") <> "", IF(field("Due date") - TODAY() < 0, 2, IF(field("Due date") - TODAY() <= 3, 1, 0)), 0) + IF(field("QA Status") = "Failed", 2, 0)

Whether you copy+paste it or manually type it, I promise it will never let you!