They have been reorganizing the race groups since 6.3. Some races from Endurance Champions will go to Endurance Legends (IDK if I'm losing my 10 lap farming, as I don't have Endurance Legends unlocked yet).
https://www.ea.com/games/real-racing/real-racing-3/news/career-and-car-changes
RR3 optimizes your graphics based on your device hardware.
You may try this App to use higher quality but be aware the Monkeys don't aprove changing your graphics
AND the game might not work if your device can't support higher graphics modes
https://play.google.com/store/apps/details?id=lt.mvbrothers.graphics
grid is actualy on android. At the moment it is in beta but it works quite nice.
https://play.google.com/store/apps/details?id=com.feralinteractive.gridmpdemo