Android app hangs on white screen for some channels even on demo server

I first ran into this problem today with the town square channel on our local server, but I’ve reproduced the problem with the demo server as follows:

  1. Using desktop browser: create account on demo.mattermost.com, login, start Development demo, and post a test message in the private Development channel. All good.
  2. Uninstall Android Mattermost app and install latest (says last updated 12/16/19).
  3. Using app, sign in to demo.mattermost.com server. Town Square channel displays fine.
  4. At some point the Development demo ended and I got a notification from the app. Clicking the notification should have taken me to the Development channel but it just hung on a white screen.

More info:

  1. Restarting the app has no effect. It tries to drop me into the Development channel when it starts up, and that hangs with the white screen.
  2. Reinstalling the app allows me to start in the Town Square channel which displays fine. However, as soon as I switch to Development channel, I get the white screen.

Even more info:

  1. After resinstalling the app, I ran through all 3 demos on the demo server and watched them until completion on my phone. I was able to switch between each of the demo channels and the town square channel without a problem. However
  2. If I close the app and re-open it (not just switch to another app and come back), and then try to switch to one of the 3 demo channels, then I get the white screen hang.

What Mattermost server version are you on?

We are running 5.6.0, and demo.mattermost.com is running 5.7.0. From what I’ve since heard elsewhere, that is the problem. The new client requires 5.9 or above.