I can confirm the problem. Actually any angle limit which is not 90 results in the problem, and just as you described, only by uninstalling and reinstalling i managed to get out of this situation.
Also note, while i reported for the EyeX that the angle limits do not work when pitch mirror is switched off, the switch can not be used at all any more with the 4C. So while i know that the reported problem if the bigger angle always being the limiter still is true in ISE version 2.0.3.593, i guess i won’t be able to cofirm a fix for that any more, as i intend to stick with the 4C in the future. Still i would appreciate it a lot, if the mirroring for limits could be unlocked for the 4c and the lower limit could be set properly.