RCConnection Error: setSDP Error: Failed to set remote offer sip: Called with SDP without DTLS fingerprint

I am using Restcomm's Android SDK and trying to configure it to our servers, but getting the following error:

RCConnection Error: setSDP Error: Failed to set remote offer sip: Called with SDP without DTLS fingerprint

But when I changing back to Restcomm servers it works fine.

I have tried to search it at Google and Git, but the solutions offered there did not help. Any idea how to solve the issue ( please explain in details since I am new in WebRTC ) ?

EDIT:

In case when I call from mobile to web or from the web to web it works fine. The problem occurs only when the mobile tries to accept the call.

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