Try this:
https://github.com/FYSETC/Marlin-2.0.x-FYSETC/tree/S6/BUG-FIX-CLCD
my S6 and 5" work excellent, did edit the configuration.h π //=============================================================================
//========================== Extensible UI Displays ===========================
//=============================================================================
//
// DGUS Touch Display with DWIN OS
//
//#define DGUS_LCD
//
// Touch-screen LCD for Malyan M200 printers
//
//#define MALYAN_LCD
//
// Touch UI for FTDI EVE (FT800/FT810) displays
// See Configuration_adv.h for all configuration options.
//
#define TOUCH_UI_FTDI_EVE
//
// Third-party or vendor-customized controller interfaces.
// Sources should be installed in 'src/lcd/extensible_ui'.
//
//#define EXTENSIBLE_UI