Your problem is the device itself: CT means China telecom
These are different from the common Mi4 LTE CU and are using different rom available on Chinese forum only
Consider this downloads http://www.miui.com/download-241.html#382 and explanation here on official forum http://en.miui.com/thread-29491-1-1.html
Thanks so much for that! It was driving me crazy not knowing what I was doing wrong. Seams so simple to flash a ROM, done it on my Mi4 and friends Redmi 2, but this Mi4 gave me a headache. Haven’t gotten around to try your advice yet but it makes perfect sense... mystery solved. Thanks again!