There is an error when trying to open another file from Finder when Emacs.app is already running. This erorr is reported in Console:
LaunchedApplication: failed with error -13052 (null){ "ApplicationType"="Foreground", "BundleIdentifierLowerCase"="org.gnu.emacs", "CFBundleExecutablePath"="/Applications/Emacs.app/Contents/MacOS/Emacs", "CFBundleExecutablePathDeviceID"=16777220, "CFBundleExecutablePathINode"=8621172431, "CFBundleIdentifier"="org.gnu.Emacs", "CFBundleName"="Emacs", "CFBundlePackageType"="APPL", "CFBundleSignature"="EMAx", "LSASN"=ASN:0x0-0x49b49b:, "LSBundlePath"="/Applications/Emacs.app", "LSBundlePathDeviceID"=16777220, "LSBundlePathINode"=8621172365, "LSDisplayName"="Emacs", "LSExecutableFormat"="LSExecutable#!Format", "LSLaunchDLabel"="org.gnu.Emacs.5196", "LSLaunchedByLaunchServices"=true, "LSLaunchedWithLaunchD"=true, "LSLaunchEventRecordTime"=154695413870065, "LSLaunchTime"=now-ish 2019/10/24 09:37:28, "LSParentASN"=ASN:0x0-0x2d02d:, "LSWantsToComeForwardAtRegistrationTimeKey"=true, "pid"=50395 }
C-h l
after such "failed" operations to see if Emacs received some event at all. If not, the problem likely can't be solved on Emacs's side and you should post your question elsewhere.M-x report-emacs-bug
.