I’ve replaced the master DNS and retired zeroshell as master. The zeroshell slaves _seem_ to be traferring the zone sanely and the missing + character is present using an alternative master DNS
I am getting some unexpected latency however – one of the two slaves is persistently returning the old incorrect record despite the zone having transferred OK and appearing correct when selecting “show” in the slave zone config.
Leaving it till morning. Uncertain why it would be returning what is now a stale record that doesn’t actually exist in the zone anymore.
Have tried restarting slave DNS services and restarting the slave zeroshell instance. Will advise if this second issue (stale record returned) is still present in the morning. (1:00AM here)