I have a rb2011uias-2hnd-in

The network consists of a satellite modem sitting on 192.168.1.1 connected to Eth1

I have two networks 192.168.88.0/24 and 192.168.89.0/24 which are attached to eth3-10 and the wifi

To configure the sat modem I need to connect to sat modem and be sat on the same subnet as the sat modem.

I thought by setting a DHCP on my Sat Config port Eth2 with a 192.168.1.0/24 would allow me to connect to the sat modem through the mikrotik but I have noticed that it uses 192.168.1.1 as the mikrotik gateway.

Any thoughts?

I'm assuming your Sat modem is handing out DHCP on 192.168.1.0/24 already. If that is the case, I'd remove the DHCP server (and any 192.168.1.0/24 IPS) from eth2 and set eth2 master port to eth1. That would link the two ports together and allow your computer to get an IP from the Sat modem and not have to do any extra steps in the mikrotik's config.