Tested with Bind 9.11.0-P5:

From the 9.11.0 changelog:

"The serial number of a dynamically updatable zone can now be set using rndc signing -serial number zonename. This is particularly useful with inline-signing zones that have been reset. Setting the serial number to a value larger than that on the slaves will trigger an AXFR-style transfer."

An AXFR-style transfer will only be triggered if Bind does send NOTIFYs after the serial was increased with "rndc signing -serial". But this is unfortunately not the case.

We do work around this issue by manually triggering them with "rndc notify". But IMO it is a bug that Bind is not sending NOTIFYs by himself after increasing the serial.

Thanks
Klaus