Redstone ores sometimes don't turn off. I were doing project using redstone ores, when i once ran over them this one didnt turn off. Here is video of it (only not turning off, i didnt record liting it on) https://youtu.be/OeccvmPWVIs . My world had some special gamerules on: doWeathercycle off, doDayLightcycle off, Immiedate respawn on, keepInventory on, sayDeathMessages off, doMobSpawning off. I dont remember anything unusual going on before/after this situation
what is your randomtickspeed?