When staff hourly rates for all clients/cases, a particular client or a particular case are changed, the new rates are applied to future time entries.  Old time entries are not changed. If you desire to change old time entries for the new rates, you will need to change them manually. System cannot make those changes automatically for various reasons including the reason that some of those entries could be fix charge entries, some of those entries may already have invoiced and also when rates are changed the changes are typically intended to apply on future work.

To change the previous time entries, the ones that are not flat charge entries, simply click on the edit icon in the note listings, when the screen opens up, simply enter the same time in Tenth Hour box.  The cost in the Total Cost box will change to new rates.  Then click save.