The latest upgrade limits how long a “partial reply” will remain in the editors “memory” to 48 hours.
The editor being the window responses are typed into, prior to selecting “Submit Topic”.
The new “fix” seem to have a bug. After clearing the previous editor window, and starting to compose another response, if you refresh, or leave the thread and return to the same editor window, it repeats the process using the “original”, “cleared”, partial response.