Some chats in some channels do not appear in the Android app though they appear in the windows app. This symptom is unpredictable. Some channels don't show history before a certain date or after a certain date. Other channels are simply missing specific chats. A notification will appear on the device and when tapping the notification, the chat cannot be seen, just the spinner.
Deleting the app, clearing cache, and clearing the cache partition on my Galaxy S9 Android Version 9 did not fix the problem. Installing the Android app on a different device exhibited the same problem.
This bug is not found in the windows app using that same account.