For a instance, admin onboard a tutor and he sets a 20% commission. (remember the site default is 25%) Tutor gets 2 bookings, so tutor pays 20% commission on those 2 sales.
If the admin changes the tutor commission. Then if we make a transaction, it reflect to the default commission rate 25% set by the admin.
So whenever the individual commission is not given, it will take the default commission set by the admin.