Azmeel

Tested enabling hide hand as recommended in this comment. Confirm enabling hide hand fixes the bug. Pls mojang fix it.

Thank you for linking this to MCPE-220838. I have added
detailed technical data as a comment on that report, including
FPS profiling data that identifies the stutter as a render
thread spike. Hope this
helps with the investigation.

This issue also happened to me and I have additional technical information.

My Device: ASUS ROG Phone 9 Pro
Chipset: Snapdragon 8 Elite (Adreno 830)
Android: 16
Versions tested: Multiple stable and beta versions including
1.26.30.21 - issue persists across all versions.

FPS data captured via in-game debug screen:

Normal gameplay (no item interaction):

• FPS: 96.5

• Render thread: 8.764 ms

• Main thread: 8.044 ms

• GPU Time: 8.120 ms

During item swap / block placement:

• FPS: 1.4

• Render thread: 32.692 ms

• Main thread: 9.157 ms

• GPU Time: 8.120 ms

GPU time remains completely constant during the stutter,
suggesting this is a CPU-side render thread issue rather
than a GPU or shader compilation problem.

Stutter pattern:

• Walk for a few seconds, then swap item = stutter occurs

• Immediately swap again = no stutter

• Walk again for a few seconds, then swap = stutter returns

Screenshots attached.