For this to happen, you must get very close to them, covering almost the entire screen. Getting close already reduces your FPS. It's worth noting that the flags must be fully configured with the loom table. Use any color and place patterns on the loom table to the maximum, until it prevents you from placing any more. The FPS drop occurs when you place the flag in one location and get very close. As for the End Portal, this has occurred since very early versions, and I linked it to this issue because it's very similar to the flags. To replicate it, simply get very close to the End Portal or watch the credits after completing the game, and you'll notice a significant FPS drop.
Linked issues
Comments 2
@clamlol , Since my PC doesn't allow me to record comfortably to appreciate the Bug and also above all, Minecraft with its errors on Intel systems (The black screen appears when capturing images and videos since several versions up to Minecraft 1.21. 5) I will tell a friend to help me record. It may take a long time or little time to deliver possible proof of the error, but it should be noted that if you have a very powerful computer or efficient enough to run heavy problems, the Bug I mention will not be noticeable at all since it mostly affects users with poor computers.
I can’t reproduce this. Please upload a video recording of the issue with the debug screen (F3) enabled with the FPS chart (F3+2), as well as your system specs, showing. You can record your screen using:
On Windows, the built-in Snipping Tool app (shift+win+S)
On macOS, the the built-in Screenshot app (shift+cmd+5)
Third-party software such as OBS
It is recommended that you trim and/or reduce the quality of your recording so it is under 10MB, as this will make the upload much quicker.