GH6 AF-C Issue ?

[Beritar]

Hi,

I think I have an issue with my GH6. I have not used this camera a lot because I mostly use my S1 and my S5II but there is something weird about the AF-C in video. Something I never seen on any cameras I've owned and one of the reason I always found the camera to be very soft in video.

Here is my issue :

When I use AF-C in video ("Continuous AF"), the AF is fast but it is not accurate. Whatever the AF (speed/sentitivity) settings or the AF mode I use ("1-zone" on the video I've posted).
I can clearly see the difference when cropping inside the videos in 4K/C4K and 5,7K below 48fps (24/25/30fps). Everything above 30fps works well (48/50/60/100/120fps), 5,8K  Open Gate 30fps works well too but with a lot of pulsing (the Open Gate on my GH5 is faster and has less pulsing).

The most surprising is before recording (with "Continuous AF" "Mode 2" activated), the focus is perfect, but right away when I press the rec button the focus become innacurate.
The AF-C is still working but it is innacurate. Easy to see with the "Enlarged Live display(Video)" function. I can still get accurate focus while recording but I need to use AF-ON or to push the shutter button to force the camera to get the good focus while recording, but of course it's not a solution.

I own some M43 lenses (Pana 10-25mm, 25-50mm, 15mm, 25mm II, 12-32mm, 100-400mm, Oly 25mm Pro, Oly 45mm Pro) and all my lenses are impacted but not the 25mm f1.4 II. This is the only lens to have accurate AF-C in video when using frame rate below 48fps, no need to press the AF-ON button, so it's really weird.

All the lenses and the GH6 have their last firmware. I have of course tried to reset the camera. "Focus limiter" is off. 5,8K Open Gate and Burst photo AF-C have accurate focus (as well as every video modes above 30fps).

A exemple of the issue with the 10-25mm in 4K 30fps and 5,9K 30fps. In 4K 30fps the continuous AF is not accurate unless I push the AF-On button. In 5,9K, there is a lot more pulsing but the focus is accurate.

So, either my sample is defective (but why only with C4K, 4K, 5,7K below 48fps ?) either the GH6 has a big issue with the AF. Maybe someone using the GH6 could test ?
Thank you.