FC2 sometimes restricts high‑resolution streams to Japanese IP addresses. A can bypass this limitation:

If you currently have a stuttering, desynced, or green-glitched copy of FC2PPV-3175924, do not despair. Use the (Method 1) to salvage your download in under 2 minutes.

A 4K fix is only effective if the export settings are handled correctly to prevent further quality loss: : Use H.264 or H.265 (HEVC) for efficient compression.