management IP cant be created while DHCP is enabled

Hello A1

I see that you already is in TMOS, so it's not necessary to use the tmsh command, except if you go back to Linux.

For exemple:

Linux ---> [Admin @ bigipalpha: Standby: In Sync] ~ tmsh modify sys global-settings mgmt-dhcp disabled

TMOS ---> admin @ (bigipalpha) (config-sync In Sync) (Standby) (/ Common) (TMOS) modify sys global-settings mgmt-dhcp disabled

The use of the TMOS is that the commands are friendly and is possible to use TAB to autocompletion.

I hope it was useful.

Best regards.