some request is not sent inside the random controller

[earlif]

Expected behavior

Random open google, bing or baidu in 20 loops. google, bing, or baidu are opened randomly, and the total request amount is 20.

Actual behavior

bing is opened only once. The total request amount is less than 20.

Steps to reproduce the problem

1. Create a new thread group, and set [Loop Count] to 20

2. Add a [Random Controller] into the created Thread Group 3. Create 3 [HTTP Request] to open bing, google and baidu

4. Start the script

JMeter Version

5.5

Java Version

tested on java version "1.8.0_301" and openjdk version "11.0.2" 2019-01-15

OS Version

MAC 13.0.1 (22A400)

[earlif]

bing is opened as expected after I disable the HTTP Cache Manager.