By comparing the two definitions attached the only difference is the open api version (3.0.1 against 3.1.0)
sample-api_3.47.0_ALL.json
sample-api_3.48.0_ALL.json
The operations are detected as changed and only repeat the parameters e.g. query, sort request parameters in one case, path parameters in the others) while nothing has changed in the operations.
testDiff.html
If we change the open api version in one definition to match the other, no changes are detected as expected
Report was generated by using the example code in home page by specifying rendering all changes i.e.
HtmlRender htmlRender = new HtmlRender("Changelog", "http://deepoove.com/swagger-diff/stylesheets/demo.css", true);