When I try to highlight the text within a column's field using Shift + arrow keys, it copies that same text to other tasks

As mentioned in the title, when I try to highlight the text within a column’s field using the Shift + arrow keys (to edit the text quickly, like in a User Story), it instead highlights the other tasks and copies that same text in place of the other tasks. There is not an “undo” button for this, so it is time-consuming to correct. Could this feature be disabled, at least for text fields? I understand the usefulness of it, but it is frustrating when you expect to highlight text and get another function instead.