quicly blocky artifacts on sony a6400

[artkam]

Hello. I use sony A6400 and noticed about some blocky artifacts when use 25fps andISO more than 3200 and object move quiclly. i used good transcend card 128gb v30 and this problem is not in low bitrate. I test some cases and discovered what this artifacts become on all PP besides SLOG2 and SLOG3 and only on 25,30,50,60 fps, not 100-120fps, ISO > 3200. Anybody has this problem or it's defect of my camera?

This example includes settings: HLG1 4k 25fps, ISO 5000 https://yadi.sk/i/7GE68PqfjElfgQ

Edited February 26, 2020 by artkam