This test is failing, and I was able to reproduce the issue locally.

The error is:

java.lang.AssertionError: expected [20] but found [24]
	at org.testng.Assert.fail(Assert.java:96)
	at org.testng.Assert.failNotEquals(Assert.java:776)
	at org.testng.Assert.assertEqualsImpl(Assert.java:137)
	at org.testng.Assert.assertEquals(Assert.java:118)
	at org.testng.Assert.assertEquals(Assert.java:652)
	at org.testng.Assert.assertEquals(Assert.java:662)
	at 

I've also seen it report "found [28]".

You can see it here:
https://github.com/apache/pulsar/runs/440479242
I've attached the Github CI logs here:
logs_16251 (1).zip

I've also attached the log from running it locally:
testSharedSingleAckedPartitionedTopic_log.txt

Note that the logs are from running this test in my branch. One change to this test is that I changed the names of some of the variables to make them more readable.