Turning on DHCP client

I have an SXT LTE6 Kit. I’ve configured it so that the LTE modem is connected to ether2 in passthrough mode. Ether2 port is wired to the WAN port of my router which is made by another manufacturer.

I can use the ether1 port to configure the SXT by connecting the POE adapter to my laptop. Then I can use Winbox to connect to the default ip address 192.168.88.1. I’d like to be able to configure the SXT from anywhere in my network. I’ve tried to connect it to my network switch, but then I can not get a connection. I think this is because the SXT works as a DHCP server and conflicts with the router which is the main DHCP server in my network. I’ve tried various ways to turn off the DHCP server from the SXT and and turning on the DHCP client but always end up making it inaccessible and have to reset and restore a backup of my configuration.

How could this be done?

Exactly that way you write.
You use bridge ? He should have only ether1 as port. Ether2 should not be assign to bridge.
You should first connect via Ether1 by MAC address, you try that ?
With WinBox via Mac Address you can disable dhcp-server, create a dhcp-client and your sxtr will be in your network at that IP what he get from your dhcp-server in main router.

To know what cut you from “network” you should connect to RB via L2 WinBox.