Cannot add TV to Home app, but is working fine in Homebridge web UI
I am unable to add 2019 B9 TV to the iOS home app. However, the plugin works as expected using the homebridge-config-ui-x web-ui.

I know I have to manually add my TV to the Home app. When I do this, two instances of the TV show up: both the native HomeKit integration (LG webOS TV) and this plugin (LG TV) as defined in my config.json. However, selecting the plugin's TV results in an "unable to add accessory" message after trying for a while. 
I have tried resetting homebridge, deleting the persist and accessories folders, and then adding back every accessory manually, but the TV still doesn't work.
As the web-ui does work, I have no idea what I can try next. I think my config.json is correct, otherwise the web-ui should give issues, but it doesn't. Why does it work in web-ui but not on iOS? Any suggestions?

Running Homebridge v1.1.6 and homebridge-webos-tv v2.0.5, TV is 2019 B9 model.