I am using basic web part page with ootb layouts. on the left wp zone I added 3 webparts related to people search result, statistics and paging. I added same # of web parts on the right side web part zone. On the left zone's people search result consumes built in federated people search. On the right people search result consumes a new federated location (which is also people search but customized to search in firstname and lastname).

Both web parts renders fine (meaning the look and feel are same on both people results). However, as soon as I put in a cewp on the page, then web part consuming custom federated result shows up like it's regular search result. See attached picture.