Tried the second option, and replaced my content_script.js with that to no avail. Seems like it isn't executing.

Someone on StackOverflow mentioned that because It's a school page, it could be an iframe(?)

On my console, this starts popping up (other things are here and there on different pages, but..) this pops up on the pages that the URL doesn't change and I can't edit the page as I should be able to.

WEBLIB_PORTAL.PORTAL_HEADER.FieldFormula.IScript_UniHeader_Frame?isFrame=true&PORTALPARAM_PTCNAV=FU…:282 Mixed Content: The page at 'https://myREDACTED.REDACTED.edu/psp/pfulprd/EMPLOYEE/HFULPRD/c/SA_LEARNER_SERV…OLLECTIONS.FUL_STUDENT_CENTER.FUL_S200711261443438320871608&IsFolder=false' was loaded over a secure connection, but contains a form which targets an insecure endpoint 'http://www.REDACTED.edu/SearchRedirect/RedirectPage.aspx'. This endpoint should be made available over a secure connection.

Makes me think I have to look into this whole iFrame thing? Also, does jQuery get included under background scripts, listed right before background.js in that array?