Game freezing intermittently

I am experiencing a bug where the game will periodically freeze for a brief moment, then continue as though it is attempting to recover from lag.

What I expected to happen was...:
I expected Minecraft 1.21 to run without suffering freezes / lag spikes.

What actually happened was...:
The game freezes periodically. This freezing is correlated to a gradual build-up in memory (according to the F3 debug tooltips), and then a sharp drop in memory during which the game freezes. The memory will then gradually accumulate again, and the cycle repeats. Note that this behavior can be observed in the pause menu as well.

Steps to Reproduce:
1. Launch Minecraft in version 1.21.
2. Create a new world (I have not tested if this bug will manifest in older worlds that are loaded in 1.21, but it seems to manifest in new worlds regardless of world type).
3. Open the F3 debugger tooltips.
4. Watch the memory measurement ("Mem" displayed in the top right of the screen)
5. Note that the game briefly freezes, after which the memory percentage is much lower. This freeze is easily noticeable while moving, but no user input is required for the freeze to occur.
6. Open the pause menu and move the cursor between buttons
7. Note that the game briefly freezes in the pause menu as well, indicated by a delayed response in updating button highlights.