For anyone that comes across this I sorted this with adding a new config under Admin > Config with the key “cwmp.auth” and the value
AUTH(“username1”, “password1”) OR AUTH(“username2”, “password2”) OR AUTH(“username3”, “password3”) OR AUTH(“username4”, “password4”) etc
.
I’ve 24 got user/pass combos in so far but not sure how many until I hit a limit.