Skip/seek issues

On app beta 8.13.1517, but has been happening for some time randomly.

Playing back local content library, like movie files, bluray rips, or other files, most are MKV HEVC, but it happens on mp4 and h264 files.
Playback set to Original.
Set to seek back 3 secs and forward 7 secs.

I am having seek issues, in that i press the right dpad button to seek/scrub forward, and it just tries to, but just plays back the last sec and continues, it does not seek forward. If i quickly press the right button to seek multiple times, it also gets stuck like, sometimes immediately sometimes it will seek a few times, then get stuck and not seek more. It does it alot more with larger files. Also, it sometimes just freezes is i long press the button to FF. Have similar behavior when seeking backward.

Not sure if it is a buffer thing on the client, current model Apple TV 4K 128GB, it should not, there is plenty of space on the thing, barely any apps installed.
Show stats says total cache 125.36MiB 92.7s video + 91.6s audio. But I can not seek forward by pressing right. ( is there a way to increase this cache amount limit)

I submitted diags from the app, when it is in a state that it will not seek forward at all with quick presses.

Backing out of the video, and starting playback again, sometimes it is fine. also, clear disk cache seems to help, but not each time.

Rebooting the Apple TV also clears it up for a time short time.

All is hard wired ethernet. Speedtest from app to server says 984.6us 940.4Mbps, 938.9Mbps

EDIT: Changing to 10 secs skip forwards seems to be more stable, but still gets stuck sometimes.

Also, i notice, now that the timeline bar shows hr:min:sec, that seeking is not always accurate.
That is, i trigger skip forward or back 10 sec, it is sometimes 7 secs, or 9, or 10.
3 sec back, sometimes does 5 sec or 9 sec. It is all over the place.