Bug - Auto Frame rate

Hi, I have tanix tx9s and CoreElec does not work properly with the auto frame rate function, when I choose an iptv channel it does not set my frame correctly, it sets me 50 instead of 25, and when I set whitelist, it sets me to some channels, and to others it does not and every time I change the fps, even if the next channel is 25 fps, I still get the black screen every time, but at 50 fps it is not. In YouTube still does not set me correctly, 2 times change my frames, 2 times black screen, this happens when the whitelist function is activated, Without the function activated the 24 hz videos still do not set me correctly sometimes, 2 times black screen . Please solve the problem … Thanks.

Only I have this problem?

Which CoreELEC Version are you using ?
Please confirm your box specs. I had to Google the specs. Please verify.
CPU: Amlogic S912
Core: 2.0GHz,Octa Core
RAM Type: DDR3
Ethernet Speed:100M/1000M ???