Macbook Pro 2017 resolution

I’ve got a 2017 Macbook Pro with a Radeon 560. In game, I get options of Low, Medium & High graphics options. On High I comfortably run at 70+ FPS. When looking at the log file, Zwift always starts with the Basic profile, and there’s no sign of it changing to a high setting when changing resolutions. I’ve manually played around with the config files and have successfully run 1440p with Ultra settings at around 35 FPS. Should this should be selectable in game if the laptop is capable of running it?