Game breaking Zero Damage Kog'Maw bug [GAMEPLAY]

happened about 3x noticeably in my last game. 5-10 auto attacks vs either morgana or karma did literaly zero damage. player from other team also saw this happen. both were able to walk around freely while being attacked and take zero damage

items used by build order: devourer (sated)--- guinsoos rageblade---- ruined king--- wit's end--- runaan's huricane--- black cleaver

(may have had nasus' wither on me 1-2 of those acounts)

bug was spoted first time roughly before wits to after runaan's moving after atacking and doing no damage reset whatever it was and caused damage again

someone knows please tell me where i can find relevant logs from that game to attach