Symptom:
No video after hold/resume in a secure conference. 
Some times call will drop when merge secure conference.
No secure lock after hold/resume in the second time's secure conference.

Conditions:
No video after hold/resume in a secure conference. 
Some times call will drop when merge secure conference.
0.users devices and MCU are all set as secure.
1.start a secure conference. Video ,audio and secure lock work well
2.hold/resume. Secure lock works well,but no video.
3.One side ended call.
4.Start another conversation  then merge conference
5.Hold/resume. No secure lock