The Moon orbits Earth relative to the distant stars in about 27.3 days. The zodiac circle is divided into twelve equal sections, so on average the Moon spends a little over two days in each one. That is an average: the exact time of a sign change is calculated from the positions, not found by simply dividing the calendar.
Pluto is a dwarf planet on a much more distant orbit around the Sun. One revolution takes about 248 Earth years. Its path is elongated, so its speed along the orbit varies; an observer on Earth also sees periods of apparent backward motion. That can mean a return near a sign boundary, so dividing 248 years evenly into twelve parts in advance would be misleading.
Astrology continues to include Pluto despite its astronomical status as a dwarf planet: that is a choice within the tradition. So a lunar sign change is marked on a specific date in the calendar, while Pluto’s sign change is considered on a scale of several years.
The stars speak. The choice is yours.