When the user uses the Language Selector Widget to change the language of the UI the portal updates the user
The following module is visible in the stack trace:
at com.liferay.portal.service.impl.UserServiceImpl.updateUser(UserServiceImpl.java:2791)
Environment
DXP 7.2, DXP 7.3
Resolution
The Language Selector is a shortcut to Global Menu > Control Panel > Users and Organizations > The specific User's General tab of settings > Language configuration
This means it is an update from the Control Panel itself, which concludes if it is modified it is needed to be saved/updated, and because of this the following module is called: com.liferay.portal.service.impl.UserServiceImpl.updateUser
