I have a similar problem.
I use the same chip, BCM20736S, the same function call,bleprofile_Discoverable(HIGH_UNDIRECTED_DISCOVERABLE, NULL) and got the same issue, random happen to stop the advertisement, except power off/on again.
The difference is that I just only using the above function call, and do not follow with ibeacon_start() or any others function.
It normally executes advertisement will LED on/off function by I/O control directly for several days. The best one could be working properly over months. When trouble happens, we see only LED blinking, but no advertisement data be detected, anymore.
We guess it could be caused by power noise to stop RF block function in IC. But, after deep sleep can not wake it up to work when the trouble happened. At that time, its same as above description, we only see the LED blinking, but no any advertisement data be received again.
We do not find the solution, yet.
Anyone could give me a suggestion?
Thanks a lot.