Avoid reopening the COME installer after success
Once Android has installed COME, open the installed app through its app entry. Tapping the saved APK can reopen the installer instead.
Recognise the two items
The APK in Downloads is an installer file. The app icon in the device's app list opens the installed application. Similar names can make these seem interchangeable, but they lead to different stages.
Confirm the previous result
If you are unsure whether installation finished, check Android's app list and the last installer message. Do not infer success from the browser's completed download alone. A cancelled or failed installer needs separate attention.
Handle later problems correctly
A sign-in or in-app network error is not solved by repeatedly reopening the installer. Record the later screen and use the related help route. Preserve account access before considering any reinstall.
A useful next step
Use the recognised installed-app entry to check the first screen and continue the account task.
Related: You declined a permission during COME setup