I don't know when it changed, but in build bugfix-2.0.x.9e8021d this controller produces a scrambled screen. It may have something to do … | Marlin, Arduino, Sensor
BUG] Anet A6 "garbage" on LCD screen in 2.0 (works in 1.1.9) · Issue #16278 · MarlinFirmware/Marlin · GitHub