This symptom is usually a conflict between the Chime Master dedicated keyboard and an organ keyboard in dual systems.
Sound restored when exiting then re-entering Record Mode
If exiting the record mode then re-entering restores the sound, this may be symptomatic of the keyboard that the carillon is connected to sending volume control messages. Many MIDI adapters on organs use the Swell Pedal to send the Chime Master volume control data. If you close the swell shades before disabling the bells with the MIDI stop, the system will remain at the low volume.
Always open the swell shades before dis-engaging the Chime stop.