Contacts are triplicate copies on my devices

Hi guys, since the last iOS update the contacts on all my devices are triplicate, the three has the same info and it happened on my iPhone, iPad and iMac but if i go to my iCloud by web browser and check the contacts there are Ok no triplicate or something like that.

Does anybody have an idea how to fix this? and more important, How did this happend?

Thanks for your help

PERCY