so i created a new world and put keep inventory on true, then i just went on playing, but when i got a full set of iron tools and armor i died in lava and lost it all, as if i never issued the game rule.

it basically just prevents keep inventory gamerule from working (this bug only seems to happen on pc, all tho the only other version of minecraft i have is the playstation 4 version, so you may want to ceack the other versions to)