Jenkins is not showing all executed Tests / Test Results in Build Overview - maven

Question

I am executing my Selenium WebDriver Tests with Junit via Jenkins, the test execution itself runs on Sauce Labs. My tests run on our company website, which is present in many countries, so I created execution profiles for maven to run the tests either on all domains or a single specific one. My POM for surefire and profiles looks like this:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.19.1</version>
<configuration>
<parallel>all</parallel>
<threadCount>10</threadCount>
<groups>${testcase.groups}</groups>
</configuration>
</plugin>
<profile>
<id>all</id>
<properties>
<testcase.groups>categories.AllDomains</testcase.groups>
</properties>
</profile>
<profile>
<id>germany</id>
<properties>
<testcase.groups>categories.Germany</testcase.groups>
</properties>
</profile>
<profile>
<id>poland</id>
<properties>
<testcase.groups>categories.Poland</testcase.groups>
</properties>
</profile>
All tests are correctly marked with the necessary #Category categories.
If i select a single domain and run the tests, all tests are executed and Total Tests / Failed Tests are correctly shown in Jenkins.
But if I run the tests on all domains, Jenkins shows me different amounts of Total Tests / Failed Tests every time. So the feedback I get from each build is different and totally unrealiable, as also the Failed Tests are not correct in comparison with the execution on Sauce Labs (Sauce Labs also has a constant amount of Total Tests / Failed Tests).
The image from the link shows my Jenkins Test Graph, the marked sections all have the same execution configuration to run on all domains, but have totally different numbers of executed tests.
Thanks to Sauce Labs, I know that all my tests specified by the profile are running, as you can see in the Image the number of Total Tests is consistent.
By now I checked all my Code and Jenkins configurations 10 times and cannot find a reason, why this is happening. So why is Jenkins not showing the actual result?
If I go into the execution data and check each class, I can see that it adds and removes random tests per domain (but still executing them on Sauce Labs), no pattern, no repetition!
PS: the config for profiles and Domain execution hasn't changed in a while, this issue started out of nowhere (no updates to Selenium code, Jenkins Plugins, Jenkins itself)

Answer 1

After some more testing I found out it is an issue with the parallel test execution in Surefire. It seems running with parallel=all started to cut off report XMLs and Jenkins did not receive all the feedback for all tests executed.
As I was using parallel=all to decrease the overall test execution time, I looked into forkCount to keep my time low without parallel=all.
So my new Surefire config in my POM looks like this now:
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<version>${surefire-version}</version>
<configuration>
<parallel>methods</parallel>
<threadCount>10</threadCount>
<forkCount>2</forkCount>
<reuseForks>true</reuseForks>
<parallelTestsTimeoutInSeconds>300</parallelTestsTimeoutInSeconds>
<groups>${testcase.groups}</groups>
</configuration>
</plugin>
Test execution time is still very low, but all reports are complete and Jenkins is showing the correct result!