To add to @aharbick’s comment about --timings-type=classname.
--timings-type=classname expects a list of class names not file names to be passed in. So if you are using circleci tests glob you will likely never want to use --timings-type=classname.
To make the point more clearly. circleci tests split simply takes in a list of strings and then tries to match them to the values that were originally in the test results file. So to give an example testcase line from a jUnit XML file
<testcase classname="MyClass" name="should access project data" file="tests/TestMyClass.java"/>
circleci tests split will simply look at the value in classname if you pass in --timings-type=classname. This is why this will never work if you pass in a list of file names. To use --timings-type=classname you want to have a method of creating a list of class names and not actually use the circleci tests glob command. The vast majority of use-cases will only make use of --timings-type=filename which is also the default if you leave it off.
Hope that helps clear up some of the confusion.