Originally Posted by Zeinzu
Try flashing stock again with odin but this time check clear EFS. If that fixes the issue you will have to re-activate your phone, but it should do that automatically or connect you to Sprint on your first outgoing call. I believe this wipes the NV ram and may fix your issue.
Thank you so much, it worked!
For all those wondering, in Odin, I check [Auto-Reboot] and [Phone EFS Clear], and this was in Odin3 v.185.