Hi Edga - we are looking into this issue.
For now, we have a workaround:
1. Choose 'Sign in with ArcGIS Enterprise'
2. Enter the URL of www.arcgis.com
3. Press and hold the 'NEXT' button, until you see the 'External browser' option.
4. Tap on the 'External browser' option. This will launch the default browser for the device and you can sign in using your Google account.
We'll update this post once we have a fix available.