I get a dip in my FPS I think whenever I'm around the chunks of a mineshaft. I can tell it's a mineshaft from the subtitles in my corner. Earlier in the world, I had made a camp over one and had the same FPS drops, I moved to another location (in the screenshot) that turned out to have another mineshaft far from the first and the same issue occurs. It does not go lower or higher than exactly 30 and it started happening on version 1.14.4 on Optifine and Vanilla every 10 minutes.
I do have Java updated and all other drivers up to date as well.
Thank you for your report!
However, this issue is Invalid.
Your game, launcher or server is modified.
If you can reproduce the issue in a vanilla environment, please recreate the issue.
Any non-standard client/server/launcher build needs to be taken up with the appropriate team, not Mojang.
Any plugin issues need to be addressed to the creator of the plugin or resource pack.
If you have problems on large servers, such as The Hive and Hypixel, please contact them first as they run modified server software.
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