A week ago I installed Ubuntu gnome in dual boot on my MacBook Pro mid 2012 (macOS Sierra). I followed the installation guide, disabled SIP in Recovery Mode, installed rEFInd and everything went well.
Today I wanted to go back to macOS and when I rebooted the system rEFInd did not show up, instead there was just Ubuntu loading. So I booted to Recovery Mode and reinstalled rEFInd (from that console I was able to locate my macOS files).
After rebooting I was able to load rEFInd page, but I cannot find the macOS "icon" to boot the system, just the Ubuntu one. Any hint on what may be the problem?