Symptoms
After entering your eRaider credentials and attempting to sign in using a mobile device, you encounter a loop that returns you to the sign-in screen.
Cause
The eRaider system was not able to authenticate your sign-in attempt based on the sign-in key and IP address returned for verification. This could be because your IP address changed.
This problem can also be caused by going to an incorrect link to access eRaider Account Manager. For instance, if you search Google for "eRaider Account Manager", the first results leads to https://eraider.ttu.edu/manager/pages/index.aspx. However, going to this link first is not the supported way to access eRaider Account Manager.
Resolution
1) Access eRaider Account Manager using the correct procedure.
2) If the previous step didn't solve it, try connecting to TTUnet VPN.
3) If you still cannot sign in after connecting to VPN, keep the VPN connection active and try browsing to a site other than eRaider Account Manager that uses eRaider authentication (for example, https://raiderlink.ttu.edu). Sign in to that site, and then browse back to https://eraider.ttu.edu.
4) Lastly, you can try using a different Internet service provider (ISP).
Outcome
You can access eRaider Account Manager on your mobile device.