Overworld mob spawners (spider, zombie, skeletons) that are currently in a lit condition will begin spawning mobs after a thunderstorm event. The lighting must be disabled and then re-enabled in order to stop mob spawning. Definitely a bug related to thunderstorms.
This is happening on a realm. It started a while ago and confirmed it is still an issue on 1.13.0.
Attaching screen captures found spawned and spawning mobs in a farm area after a thunderstorm event where both mob spawners were left in a LIT condition upon last use.
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Cleaning up old tickets: This ticket had been set to 'Awaiting Response', but has not received a response from the reporter (~3 months+) so is being closed as Incomplete. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines which includes steps to reproduce the problem.
Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki
Cleaning up old tickets: This ticket had been set to 'Awaiting Response', but has not received a response from the reporter (~3 months+) so is being closed as Incomplete. If you feel this is still a valid issue then please comment, or create a new ticket following the Issue Guidelines which includes steps to reproduce the problem.
Quick Links:
📓 Issue Guidelines – 💬 Mojang Support – 📧 Suggestions – 📖 Minecraft Wiki