Guys, during the struggle to reproduce the issue somehow i found something strange. Let me describe it.
Starting point: host has a valid mac, up to date. i want to change mac. It can cause 2 different output, and i think it can cause the result somehow (i will do more tests to see if it really happens, but the difference made me curious).
mac update method1: host primary mac field is the only field, no additional field. i select the full field, then overwrite mac. result is a new mac on primary and an additional mac field appears with the previous mac address (which is wrong, as it has no another, but a new mac actually)
mac update method2: same starting point, but i only use mouse click to the end of the field, without selection of any char i use backspace, for like 1 char, and type another char instead of the deleted one. here NO additional mac field comes to existence. why? if i change the mac any method i want to change it, not add a new one (i will make test with it, maybe this way it will disappear somehow)
EDIT: sorry, somehow i did not notice what you wrote before me.