Steps to reproduce:
- on a 5.2 install, login as Admin
- go to Administration
- go to Search Suggest section
- Make sure the Solr tab is selected and click on "Add a new source"
The first thing you notice is that the new source gets pre-filled with the values from the first source. Save and reload the page. Then you'll notice a blank new source under the Lucene tab and the first source gets overwritten with the values from the new source you wanted to add.