Sometimes the android app(especially vivo phone)can not scan the device

[Milk]

The vivo phone sometimes cannot scan the device, There are two devices embedded same program. However,one of them can be scanned,the other one can not. The advertising packet shows as follows:

I can not find the wide difference,how to solve this problem?

[Hung Bui]

Which app did you use to scan ? Have you tried to use the nRFConnect app ?

If you match the advertising data on both device to be the same , do you see the problem ?

[Milk]

I use Master Control Panel to scan, I change the MAC address which can be scanned(Device A) to be same with the MAC address which can not(Device B). The result is that Device A still can be scanned.

[Hung Bui]

Have you tried to send the same advertising data on both device ? If a device advertise with directed advertising to another phone, you won't be able to detect the advertising packet on your phone. This case it doesn't seems like directed advertising though. How often can/cannot you scan the device B ?