@ChrisDV the DHCP reservation does not force a specific IP if the device can connect to multiple networks. Assigning port profiles is the key here. Make sure every device is connected to a managed switch port where the correct port profile is configured. The DHCP reservation is then honored within the configured range of network segments.

To my understanding, a non-managed switch is transparent and therefore all devices behind it are virtually connected to the same upstream port which has a specific port configuration on its own, therefore the DHCP assignment will again follow the upstream port configuration.

  @ChrisDV I know, it got me confused as well. But in the end you want to manage your switch ports anyway (not allow access to mgmt LAN for non authorized devices) so you only have to ensure DHCP pool and port configuration are in line.

  @ChrisDV exactly. On the upstream switch or router, create (or select, if already existing) a profile that only contains the VLAN in which you have created the DHCP reservation for the device behind the unmanaged switch. That will work. Note that other devices connecting to the same unmanaged switch will automatically receive an IP from the same DHCP pool.

Adding two VLAN ranges to the upstream switch port profile will not work for sure, as the switch will choose any IP from all VLAN DHCP pools possible. I had the same situation and noticed that the lowest VLAN pool was used here (handing out IPs to non-secure devices in my network management VLAN...) but that may have been a coincidence.