Signed Safari app extension not recognized when signed

com.apple.SafariServices.ExtensionHelper: (PlugInKit) [com.apple.PlugInKit:discovery ] <PKDiscoveryDriver:0x7f87a72072e0> installing watchers for continuous discovery
com.apple.SafariServices.ExtensionHelper: (LaunchServices) [com.apple.launchservices:default] LSApplicationWorkspace: adding observer <PKDiscoveryLSWatcher: 0x7f87a730dac0>
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:csresource] 0x7f87a5e097a0 rule ^Contents$ added (weight 0, flags 0x12)
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:csresource] 0x7f87a5e0d660 rule ^(\.LSOverride|\.DSStore|Icon
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:dirval] entering /Applications/PLUGINNAMESafari.app
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:dirval] entering /Applications/PLUGINNAMESafari.app/Contents
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:dirval] leaving /Applications/PLUGINNAMESafari.app/Contents
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:dirval] leaving /Applications/PLUGINNAMESafari.app
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:unixio] open(/Applications/PLUGINNAMESafari.app/Contents/MacOS/PLUGINNAMESafari,0x0,0x1b6) = 3
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:unixio] open(/Applications/PLUGINNAMESafari.app/Contents/MacOS/PLUGINNAMESafari,0x0,0x1b6) = 4
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:macho] 0x7f87a5e0d850 is a thin file (x8664)
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:unixio] close(3) err: 0
pkd: [com.apple.PlugInKit:xpc ] client 51366 requested match
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:machorep] 10736 signing bytes in 4 blob(s) from /Applications/PLUGINNAMESafari.app/Contents/MacOS/PLUGINNAMESafari(x8664)
pkd: (CoreFoundation) [com.apple.defaults:User Defaults] found no value for key exclusions in CFPrefsPlistSource<0x7fda60405540> (Domain: com.apple.pluginkit.userprefs, User: kCFPreferencesCurrentUser, ByHost: Yes, Container: (null), Contents Need Refresh: No)
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:cfloadfile] failed to fetch /Applications/PLUGINNAMESafari.app/Contents/CodeSignature/CodeRequirements-1 error=-10
pkd: (LaunchServices) [com.apple.launchservices:default] Waiting on thread <NSThread: 0x7fda62817c50>{number = 51, name = (null)} until Launch Services database seeding is complete.
com.apple.SafariServices.ExtensionHelper: (Security) [com.apple.securityd:unixio] close(4) err: 0
pkd: (LaunchServices) [com.apple.launchservices:default] Got plist data 0x7fda6011fa00 for unit 166ec from database 0x7fda6480d000
com.apple.SafariServices.ExtensionHelper: (PlugInKit) discovery
com.apple.SafariServices.ExtensionHelper: (PlugInKit) [com.apple.PlugInKit:discovery ] [d 09A10057-7B99-4CAA-A7FB-4E5EDBCA2D79] <PKHost:0x7f87a7004100> Beginning discovery for flags: 0, point: (null)
com.apple.SafariServices.ExtensionHelper: (PlugInKit) [com.apple.PlugInKit:discovery ] [d 09A10057-7B99-4CAA-A7FB-4E5EDBCA2D79] <PKHost:0x7f87a7004100> Query: {
"LS:ExtensionPlatforms" = (
1,
6,
2
);
NSExtensionContainingApp = "/Applications/PLUGINNAMESafari.app";
NSExtensionIdentifier = "com.com.pluginorgname.PLUGIN-Safari";
}
pkd: (LaunchServices) [com.apple.launchservices:default] Got plist data 0x7fda5e663990 for unit 166f0 from database 0x7fda6480d000
pkd: (LaunchServices) [com.apple.launchservices:default] Got plist data 0x7fda5e663990 for unit 17a90 from database 0x7fda6480d000
pkd: (LaunchServices) [com.apple.launchservices:default] Got plist data 0x7fda5e65d7e0 for unit 17aa0 from database 0x7fda6480d000
pkd: (LaunchServices) [com.apple.launchservices:default] No plugins found to match query {
"LS:ExtensionPlatforms" = (
1,
6,
2
);
NSExtensionContainingApp = "/Applications/PLUGINNAMESafari.app";
NSExtensionIdentifier = "com.pluginorgname.PLUGIN-Safari";
}