Is GAPM_GEN_RAND_NB pseudo-random or true random?

Hi,
I've noticed thatGAPM_GEN_RAND_NB返回不同的results (viaGAPM_GEN_RAND_NB_IND) even when the same code runs twice (Unlike callingrand()which is pseudo-random).
I read that in some BLE chips there is a "true" random feature, which is based on the random radio signals that the chip receives.
Is GAPM_GEN_RAND_NB true random or pseudo random?
Can I consider it cryptographically secure? (Do I need to use GAPM_USE_BLOCK with non-secure random values to increase the security?).
What about power\time consumption in comparison to GAPM_USE_BLOCK? If it consumes too much power, I can pick 16 random bytes and use AES in counter mode, which is considered a good csprng for up to ~1MB.

Thanks

--- Edit ---
GAPM_GEN_RAND_NBdoes not always return unique results. After some executions, it returned the same results as previous ones. I am not sure what affects the results - could be some background interactions with connected devices.
I found some documentation inGAP Interface Specifications. UnderGAPM_GEN_RAND_ADDR_CMDthe documentation says: "Generate a random device addresswithoutstarting any air operation.". This is not stated underGAPM_GEN_RAND_NB_CMD. Does that mean thatGAPM_GEN_RAND_NB_CMDdoes use air operations (i.e. truly random)?.