Tests not splitting by time using Webdriver (WDIO)

I’ve finally managed to use test splitting with WDIO, and I have tweaked the JUnit reporters for each runner to output in the following fashion:

<testsuite name="Account Details" timestamp="2023-11-02T12:15:57" time="21.902" tests="1" failures="0" errors="0" skipped="0">
<property name="specId" value="0"/>
<property name="featureName" value="Account Details"/>
<property name="capabilities" value="android.rf8m41r0dwh"/>
<property name="featureFile" value="automation/features-ui/accountDetails.feature"/>
<testcase classname="CucumberJUnitReport-android.rf8m41r0dwh.Account Details" name="See my account details" time="21.405" file="automation/features-ui/accountDetails.feature">
<![CDATA[ ✅ Given I am on the site✅ When I do a thing ✅ Then I see text displayed✅]]>

This is then uploaded for each runner (so Junit-report-0-0.xml for runner 1, etc) using the store_test_results action. However, every subsequent run gives me the dreaded No timing found for "automation/features-ui/accountDetails.feature" error. Is there something I’m doing wrong in the formatting here, or am I not uploading to the right place/with the right filename? Driving me barmy.