I’m having similar issues once I upgraded to CM 8.6.2.
I use ATA and VG224 and both are heaving the same way.
I have tried sending out an ISDN and our SIP trunk and both fail.
I will also open a tac ticket to see if I can get it resolved, so I’ll let you know what they say.
Unless you got your issues resolved ... I would be curious how you fixed yours