@chadstraus97 You certainly aren't alone with this problem, here are threads posted in bugs & issues from the last 6 months:
evereid97 level 119, 16.1.2018 no part 3
https://forums.ea.com/en/the-simpsons-tapped-out/discussion/194999/sideshow-bob-never-appears-in-my-town-so-cant-trigger-flaw-and-order-part-3#latest
sherrybrow46 level 126, 30.12.2017
https://forums.ea.com/en/the-simpsons-tapped-out/discussion/190601/sideshow-bob-character-has-never-been-in-game#latest
tra0106 1.12.2017
https://forums.ea.com/en/the-simpsons-tapped-out/discussion/178652/trouble-with-completing-the-flaw-and-order-questline#latest
k1983k76 level 77 & stopIRISH1986 level 100, 2.8.2017
https://forums.ea.com/en/the-simpsons-tapped-out/discussion/125580/both-sideshow-bob-and-flaw-and-order-missing#latest
utbmicgas level 31, BchonxD level 60, erlambie0315 level 53, 3.3.2017
https://forums.ea.com/en/the-simpsons-tapped-out/discussion/93918/sideshow-bob-quest-wont-appear#latest
stinkbutt98 level 65, 21.7.2017
https://forums.ea.com/en/the-simpsons-tapped-out/discussion/120654/flaw-order-sideshow-bob#latest
d-gal 10.7.2017
https://forums.ea.com/en/the-simpsons-tapped-out/discussion/117397/cant-get-sideshow-bob#latest
Lots of players also post in general discussion, or on other sites such as EA answers. I would like to put a note in the tips thread of the best way to approach this problem and really hope you get it resolved as soon as possible.