[Gameplay] Thresh + Spoils of War (Relic Shield item chain passive ability) Bug

I couldn't find any other threads on this, but I apologise if I'm just blind and missed them.

While playing a Thresh in a co-op (easy) game, I noticed that the Spoils of War ability from the Relic Shield item chain was going off inconsistently. I proceeded to test out how to get it to activate and found that the execute function of the ability wasn't working. If I got the killing blow on a minion the rest of the ability activated as normal (the heal and gold share).

I tested it across several custom games to repeat the bug. It was also tested on multiple minion types including caster, melee and cannon. I did not test it on monsters or super minions. I also tried upgrading the item to see if that would fix it however it did not.

Following which I swapped champion to Poppy and the ability returned to normal functionality.