Well did you follow my suggestion and enable X_AcceptSipFromRegistrarOnly? And are you sure the change you made (if you did) actually stuck after the reboot?
If so, you need to look at your call history on the OBi device itself and find out exactly what line these scanner calls are coming in on. Do you know how to do that?
You need to login to the ip address of your OBi 200 on your local network in your browser. Default username and password is admin.
After login, click on Status -> Call History.
What line are these calls coming in on?
I have the same issue too. They come in as follows:
12:28:08 From PP1(ob37*6555501) Fork to:PH1 PH2
11:45:47 From PP1(ob37*1900008603) Fork to:PH1 PH2
11:37:16 From PP1(ob37*1900008603) Fork to:PH1 PH2
I did
X_AcceptSipFromRegistrarOnly