Revive Passive's sometimes not working correctly

I want to point out an issue which has been occurring as of late, for champions with revive mechanics: and the item . There are times when the passives will not proc at all despite them being off CD and ready for use, now I'm not too sure what is the cause for such a bug to occur. However I do believe that this does need to be looked into because these revive passives are core to their champions and in the case of , the champs who build it rely on that revive passive to stay relevent in the lategame where even a single death is punished by 40s+ timers.