Thanks for reporting the issue!

The application you are using to launch the custom tab does have an intent filter that says it handles the custom url scheme, right?

Do you see the intent being launched from logcat (there should be an ActivityManager entry with your app's package name)? And then do you see anything about your app being displayed?

I am trying to figure out at which point your app is being closed. It might be a bad interaction with a task flag you are using and how the custom tab sits on top of the launching app. Do you mind pasting the Activity entry for your main Activity in your AndroidManifest.xml?

I have the same issue. I don't see anything either way in the log file
Here's my activity entry 
        <activity
            android:name="com.t2.rest.ChromeTabLaunchActivity"
            android:label="ChromeTabLaunchActivity"
            android:launchMode="singleTask"

            android:theme="@style/AppTheme.NoActionBar">
            <intent-filter>

                <action android:name="android.intent.action.VIEW"/>
                <category android:name="android.intent.category.DEFAULT"/>
                <category android:name="android.intent.category.BROWSABLE"/>
                <data android:scheme="t2gspan" android:host="logincallback" />
                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available. If you change it back, also remove the "Hotlist-Recharge-Cold" label.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Bulk edit: Moving back into the untriaged pool, as I'm leaving the project.