I can't load the Bootcamp interface on powering up my iMac
I have an iMac Retina 5K. It's bootcamped with Windows 10 and OS Catalina. I flipped it over to the Windows install to do some testing, and now I can't get into Bootcamp when starting the machine up again, to flip it back to OSX. It's like I'm not pressing the option key at all. Any help?
iMac Line (2012 and Later)