Passing DTMF data with dialed number

I have been using RingCentral for the past 3+ months; I have done a lot of automation around passing DTMF along with phone number - For example - tel:8664567890,,,12345# -> This would dial this 866 number and after the call is picked - will pass 12345#.

This has been working flawlessly but somehow it stopped working a couple of days back when i started testing.

Could you please help me resolve this issue.