This problem has been present for some time. You have to edit the saved letter and write in the name of the MD. Also, if you add/change the signature such as adding another physician to cc, it stays the same the next time you write a letter. This is also nuisance. Hopefully, these will be fixed in the next version.
The other thing I hope gets fixed is to include the patient's name on each page when printing a daily batch of notes.