A scale regardless of the mode, MUST go up or down by step regardless of the interval between the steps. If a scale starts on D for example, the next note must be an E the next an F#, the next G. You would never have 2 letters the same in a Scale like G going to a G# it must be an Ab. Even if it means calling a note Gbb or an F## you must keep to the alphabetic order. The next note in any scale in any mode MUST go up to the next letter in the alphabet.
Your point is…?
Do you have an example to quote?