I've got TVH streams problems only

Hi thank you for good OS firstly

I’ve got 3 S905 tv boxes, Beelink Mini MX (S905/1GB/8GB)
Sunvell T95X (S905X/1GB/8GB sucks 9082xs wifi)
Magicsee Iron (S905X/2GB/16GB)

I installed every devices CoreELEC 9.2.0 and they works perfect entirely
but Magicsee Iron has a problem with TVH client IPTV streaming

Mini MX and T95X hasn’t problem only Magicsee Iron has problem
They settings almost same but I don’t know why

So I check my kodi.log when IPTV plays stutters

2019-11-21 01:37:23.330 T:3122668416 WARNING: CRenderManager::WaitForBuffer - timeout waiting for buffer

these messages are whole the log

IPTV formats H264 1080i, I set my KODI UI 2160p/60Hz
and any problem with other 2 devices
and when I set it 1080p/60Hz has same problem

I did search and search then make advanced.settings, I increase cache memory size to 400MB.

Cuase is it slow emmc for reason?

I used dtb gxl_p212_2g and install to internal.
I set disable deinteracing on System/CoreELEC setting
Adjust refresh rate off and refresh change to Start/Stop

I use wired internet, I checked with KODI speed test and result is up/down 90Mbps
My tv is LG so I turn on forced 4:2:2 setting on System/CoreELEC setting

How can I solve it?