no. Basic telephony won't care unless when calling in that the SBC to CM must be SRTP and comes in to CM on a TLS trunk. TCP can't do SRTP, so if CM's going out as TCP, that could be a problem, but only if the SBC/CM portion of your media requires SRTP.
More than likely you have a configuration issue in your SBC. Your media and session and endpoint flows need to define what happens in both directions. If you log in to the EMS, do you see "incidents" where something didn't match a flow? That'd be the SBC saying its confused about a call it got and didn't know how to process.