Red Lion to Emerson EN

I was given a fun task of replacing an old Maple/Emerson OIT panel with a Red Lion G307K2. The screen connects to an Emerson EN drive with FM-4 Module.
The Maple still works, but the customer received two new units that use Emerson EP drives with Red Lion screens (over Modbus TCP/IP) and wants to upgrade some old units.

From what I dug up, the Emerson EN is a Modbus RTU slave over RS-232 (19.2k, 8 data, 2 stop, no parity). I can connect to the drive with my PC and the old Maple, so the drive is good to go.

I just can't talk to the drive with the Red Lion.
I took my Red Lion file that's designed for Modbus TCP/IP and changed it to a Modbus RTU Master over the Comms port - RS232 mode.
I followed the wiring from the Kadet manual and can't get any communications. I read many other posts regarding the Kadet documentation having RX and TX flipped, so I tried flipping those as well.
I've also tried using Com 2 (setting the programming port to Modbus Master), and Com 3 (setting the aux port to Modbus Master).
My last effort was trying a G304K2 and following the wiring for that. Still nothing.
I also created new files with a few basic tags for each Red Lion with no success.

Any suggestions? Red Lion tech support wasn't much help, but I give them credit for not having me on hold for an hour like some other manufacturers
I have a feeling it's something in the driver or settings. All hardware checks out fine individually.

Thanks in advance!

Can you post your Crimson Database (zip it first)? That way we can see how you have everything set up.

Here's the basic file with the screens stripped out

Thanks