Help needed with changing Mosquitto password

I need to change the password for Mosquitto MQTT, as it is currently only 4 digits long and Tasmota will no longer accept a password less than 5 digits.

It looks like it should be in Configuration>Mosquitto broker>CONFIGURE>RE-CONFIGURE MQTT, but the Username and Password in there do not match my current ones.

Did you ever resolve this, I’ve just hit the same problem?