Aidan

You can only  report a bug in Minecraft in English. Feel free to report it in English if you can speak the language! Have a nice day!

This isn't a bug. It is probably just a performance issue.

This is not a bug because the oceans can't be generated before the aquatic update to have sea creatures. What it means to have generated oceans before is that you have already visited them, you might have just not remembered visiting them too. This isn't coming just from me by the way, Mojang said it themselves. No matter what update of Minecraft you are in.

I also experienced the same bug as you did on the same version of Minecraft as you are on.

Same thing happened to me. Hopefully someone can fix this.