CC2640: multi_role example disconnect with several Android phone

Part Number:CC2640

Dear TI Experts,

One of my customer is evaluating CC2640 with BLE-Stack 2.2 on Lacunchpad.

Here is the question:

Simple_peripheral example works fine with both IOS and Andorid.

Multi_role example for ios, can connect to it normal, and for some of android device, nexus 5, samsung s3, meizu m3, they are also ok.

However, for some android device, like nexus 4, huawei p9, after building the connection, the device will auto-disconnect 5-6 seconds with status 34, ie 0x22, LMP response timeout,

my connection param:
 min_int 80
 max_int 80
 latency 0
 timeout 1000

Could you give me some suggestions ? Thanks a lot.