I found some hint, when this software is running, lock command of Alfred will wake up this software to front , rather than lock computer.
https://im.qq.com/macqq/
OS version: 10.14.3
Alfred version: Alfred 3.8.1
Hardware Overview:
Model Name: MacBook Pro
Model Identifier: MacBookPro11,3
Processor Name: Intel Core i7
Processor Speed: 2.3 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 256 KB
L3 Cache: 6 MB
Memory: 16 GB
Boot ROM Version: 149.0.0.0.0
SMC Version (system): 2.19f12
Serial Number (system): C02MC3P4FD57
Hardware UUID: D5365CE2-9F20-5995-BF7B-F16935119E87
Problem: lock doesn't work after upgrade to Alfred 3.8.1.