For the Montessori aspect, yes, there are a bunch of “Montessori” schools that don’t really follow Montessori principles (at least there are in my area.) If you want to find a school that does actually implement Montessori principles, you have to do research (looking for membership in an association like the American Montessori Society is a good first-pass filter) and interview the school. There’s no substitute for due diligence for this.
My wife, a Montessori preschool teacher for 30 years, calls these unaccredited schools Monte-sort-of.