regarding central, near field mode

Hi,

I have implemented a central role device on DA14580 (Murata), from proximity monitor (ext) source, but using
app internally on the device using sdk app sources (app.c, app_task.c). However, several times during running,
it caught into hard fault, which I suppose, happened at ke_malloc (judging from stacked information), where a memory store instruction
试图存储内存之外的任何堆defined (I think). There are several condition that causes hard fault,
1. When the central is repeatedly connected, and disconnected, at the end, it will fault during connection attempt
2. When there is another central connected to a peripheral, and that peripheral is still giving advertisement during
connection, it will fault during attempt of connection. During which, the central accepts a gapm_connection_req_ind,
but then failed to establish connection.
My question, Is there any difference on memory map (scatter files) on externally hosted app, and internally hosted app?
I don't know how to debug further since I don't know who actually call that ke_malloc, I suppose if there is a memory
map difference, that would be the cause. I didn't change any memory settings from proximity monitor example.

Second question, pretty simple, If a central and a peripheral is connected, and the peripheral switched to near field mode,
would the connection rssi change? or should an advertisement command be requested on the peripheral before
the connection rssi could change?

Thank you very much.