Hmm, this is a little strange, so I hooked up, it doesn't have a TX pin oddly, I thought all serial needed RX and TX, even if it was one way, but I can't see any unless they call it something else, which I doubt.
However, hooked in with power, when I first give it power, it flashes the cursor as normal, then, when I plug in the usb uart adapter, it continues to work, but once I disconnect it, the cursor stops flashing, until I either cycle power or plug in the usb uart adapter again, so maybe it is recognizing that there is a serial connection?
I haven't really messed with serial much aside from the i2c lcd adapters for arduino stuff so forgive me if this is something super obvious.
It does have a reset pin, so I figure i might be able to directly talk to it with the adapter but maybe I need to stick an arduino in the way and see if it works with the i2c lcd library (which would be epic)
Edit: tried it with another uart adapter as I recalled the one I had doesn't program arduinos for some reason (but does pass the loopback test), and now when I have it connected, same as always, until I open a terminal program (realterm or arduino monitor), then the cursor stops blinking. Sent it some display codes but no luck.