"AutoSetup 1.1 for Unity 2019.3 / HDRP.unitypackage" from https://www.reallusion.com/character-creator/unity-auto-setup.html (Which is, of course, quite out of date since there have been three official Unity releases since 2019.3) No test project is really required - the plugin does PlayerSettings.SetScriptingDefineSymbolsForGroup on load setting just its own define without preserving any existing ones.
Hi tsds We can reproduce the issue and it's already submitted to dev team. Our engineers will check the situation. Thanks for your patient, please follow our latest news. Tina