I have run into that problem in the past, but not with multicast paging. The system is using multicast paging, so MGI channel usage for paging is not an issue. Also, we are using MPS on this system so MGI usage is further minimized.

Samsung support suggested that we enable "Real Ringback" under DM 5.2.18. Tested in the office on Friday and appears to resolve the issue. I will follow up with the customer today to make sure that it also resolved the issue on their system.