Not operator and DHCP flag not working on v6.2

RouterOS Scripting
1

Hi Everyone,

I use the below code to get a list of all hosts that are connected to our wireless but not authorized.

:global counter

:foreach counter in=[/ip hotspot host find !authorized && DHCP || dynamic ] do={:put [/ip hotspot host get $counter mac-address]}

It works fine on everything up to v5.25 but when I try to run it on v6 neither the not operator or the DHCP flag seem to be recognized.

I may be missing something blindingly obvious but I can’t figure what it might be.
Any ideas?