FPS is unstable at particular frame rates

Version: Steam- Aseprite v1.3.8.1 -x64
Date: August 27th, 2024
OS: Windows 11

When FrameRate → Duration is set to a particular value, frame skipping occurs when playing the animation.
Around 200ms, it pauses at a semi-random frame, skips the next frame, and displays the next one.
Around 400ms, some frames appear whose display time is shorter than the specified time.
On the other hand, this problem does not occur around 300ms.

This problem did not occur when I first started using it, but has only recently started occurring.