I don't know anything about this device, but I would try:

SIP SERVER: sip.voipwelcome.com
SIP USER ID: your phone number
AUTHENTICATE ID: your BYOD password
AUTHENTICATE PASSWORD: your BYOD password

Leave the other fields blank. It may be that your BYOD password is locked out due to your tinkering. I would disable BYOD in vPanel, and then re-enable to have it regenerate another BYOD password.