Hi,
Our user who are using the Yealink W52H are reporting that everytime they put someone on hold then it automatically cuts off the line and the call is ended. I was wondering are there any settings in the pbx to adjust this? or would it be a configuration on the Yealink side?
Just so you need to know I am running the latest freepbx 12.0.74 and they are using pjsip extensions
let me know if you need anymore information 
Thanks,
Mohammed