Playback corruption during accelerated playback (L key) in latest Premiere Pro

I am experiencing a playback issue in the latest version of Adobe Premiere Pro.

When I use the L key to increase playback speed (2x or higher), the video playback becomes unstable after a few seconds. The image becomes choppy, and GPU-based effects such as blur or mask-based effects appear misaligned or detached from the subject during playback.

Important points:
- Normal playback speed (1x) works correctly
- Paused frames are correct
- Final export/rendered files are correct
- The issue occurs only during accelerated playback
- This did not occur in older versions of Premiere Pro

System specifications:
- OS: Windows 11
- CPU: AMD Ryzen 9 9950X (16-Core, 4.30 GHz)
- GPU: Water-cooled NVIDIA RTX 4080 SUPER
- RAM: 128 GB

Additional details:
- The issue occurs with both 60fps and 30fps footage
- Resolution: FHD (1920×1080)
- It happens even when:
- Playback resolution is set to 1/4
- Switching between Hardware Acceleration and Software Only rendering
- GPU drivers are up to date
- Mercury Transmit is disabled (no external monitor output)

Summary:
This appears to be a playback-only issue related to accelerated playback, not an export or rendering problem. It seems that effects processing is skipped or desynchronized during high-speed playback, especially with GPU-based effects such as blur or masks.

I would appreciate:
- Confirmation whether this is a known issue in the latest version
- Any recommended settings or workarounds
- Guidance on whether this behavior is expected or a regression from previous versions

Thank you for your assistance.