Nvidia shield tv 2017 problem display with cores

Hello, I come to you for settings finally I guess I use a nvidia shield tv 2017 and I installed on Retroarch 1.7.7 the last stable version I have several cores on the Playstation 1, the megadrive, the super Nintendo that work very well but I also have the Nintendo 64 that does not work very well and the dreamcast or half of the games does not work Attached video to understand

The nintendo 64 I use mupen64plus and I have big problem of posting with 1080 snowboarding I do not know where it can come Otherwise for the dreamcast I use flycast and my iso are in .gdi for sega rally i tried several format but none works for shenmue the character and cut and I have the impression that there is that toy commander who passes in the lot you know why? If anyone can help me with these problems? Thank you and have a good day everyone :wink:

Please help thanks you

Can anyone help me with this problem?

Up please thanks very much