I also have High Sierra (10.13.1) and am running EOS Utility 3 (3.7.0) with a 5D IV (firmware 1.0.4) and even when I tell it I want to shoot tethered (controlled by EOS Utility) it works fine. To download a GPS log file using EOS Utility, use Map Utility 1.8.0 or later for EOS 6D Mark II, use Map Utility 1.7.2 or later for EOS 5D Mark IV, use Map Utility 1.7.0 or later for EOS-1D X Mark II, use Map Utility 1.5.3 or later for EOS 7D Mark II, and use Map Utility 1.5.2 or later for EOS 6D.