IE11 is supported until 7.9, but this feels unlikely to be a browser issue -- unless it is working for you in other browsers?
This sounds like a front-end issue so the browser console is probably the best place to look. Have you confirmed that the index pattern "ml_usrip" (f248d7b0-cb25-11ea-ab4a- is in fact set as "default" in the index patterns UI? Are you able to change to different index patterns in discover using the dropdown?