Issue with WebRTC data channels

Hello,

I successfully run and modify to my liking the WebRTC sendrecv example here:
https://gitlab.freedesktop.org/gstreamer/gst-examples/-/tree/master/webrtc?ref_type=heads

However, I am having an issue with data channels.
When I use the webrtc-sendrecv process (unmodified) with the JavaScript
example, data channels open and the browser and executable talk to each
other: "Hi! (from Gstreamer)" and "Hi! (from browser)"

However, when I run two webrtc-sendrecv executables, they are able to pass
media to each other and CREATE data channels, but the data channels never
OPEN - no on-open signal ever fires and if I try to send a message at any
point through send_channel, I get "webrtc_data_channel_send_string:
assertion 'channel->opened' failed".

I would appreciate any advice! I believe the answer must be in the way the
executable handles negotiation vs. the Javascript example, but I don't know
how to debug into those issues.

 - Ben