Visual editor - applying mixed formatting to adjacent characters broken

Applying formatting to adjacent characters that remain unformatted in the visual editor results in failure to properly render.

Example: In this sentence, the word, "*sent*ence" has the first four letters set to bold, and the remaining characters unformatted.

When we send comments to users, we will frequently mark a portion of a word in bold print to draw attention to a piece of a word or statement. An example would be when explaining to use a SAM or UPN  login to a user, where you might say, "Please use domain\username to login.)

Result: The word "sentence" would be displayed in the portal and in the email sent to the reporter in the following way, in descriptive text, so this editor doesn't re-format on submit: asterisk-s-e-n-t-asterisk-e-n-c-e