I have done a test with my OBi110 and my OBi202 connected to PSTN; Bezeq, Israel.
Every single setting exactly the same; DisconnectTonePattern: 400-30;10;(.5+.5)
OBi110: disconnects after 7 seconds.
OBi202 with OBiLine: carries on the call indefinitely.
I originally thought I had the wrong disconnect tone.... >:(
What can I do? I'm so frustrated ???
I think it might be time to escalate this and ask the obi support for help with a link to your results.