TAP Parser comes up as default test result format while loading job config UI

In Labelled group plugin open source version (1.2.7) by default config UI takes up TAP Parser as the test result format, even if I change the format and save it.

When I looked into the config.xml file it has right class name as JUnitParser after I change and save it, but somehow when I reload the config in UI it picks up TAP Parser as default, instead from the config.xml file.

Config before UI change,

<hudson.plugins.labeledgroupedtests.LabeledTestGroupConfiguration>
<parserClassName>hudson.tasks.junit.JUnitParser</parserClassName>
<testResultFileMask>TEST*.xml</testResultFileMask>
<label>Test Results</label>
</hudson.plugins.labeledgroupedtests.LabeledTestGroupConfiguration>