Please do the following steps:
1.Deactivate the virtual line from multi-line settings.
2. Log out from the multi-line settings and uncheck the box to delete any data related to multi-line settings.
3. Go to my T-Mobile and into the multi line settings of virtual line. Remove any device assigned to the virtual line.
4. Remove yourself from the virtual line.
5. Then re-add your self to the virtual line.
6. Re-login into the multi-line settings in your device and enable the virtual line.
This should rehash the system. Please post what happens after these steps.
Unfortunately the procedures did not work...
I must clarify, however, that the secondary line (let's call it line B) I
have activated on my device is not a virtual line, but one of the primary
lines in my account (provisioned to another phone/SIM that is normally
turned off). When I first went through DIGITS configuration, I added this
line B as a secondary line to my phone. I then received an SMS message
through my primary line A asking for permission to allow line B to be
utilized on another device. I authorized it and line B became "ready for
use" on my phone.
Again, I can send and receive SMS messages to/from the secondary line B,
and also receive phone calls from the secondary line B on my phone. Making
calls from line B still does not work, as the call gets quickly switched to
the primary line.