i moved my city for quicker barb farming and within 24 hours the barbs disappeared is this normal.
Yes, it's normal, as the barbarian camps disappear if:
- they have been raided 5 times in a row, in which case they disappear immediately after the 5th raid (note that these 5 raids can be initiated by different players, what counts is the overall number), or
- they have been raided at least once, and some time has elapsed since the last attack.
Those barbarians that have disappeared or those that have been raided 1-4 times, will be replaced by new barbarian camps, which occurs every 6 hours.