Yes, I am the only admin, here are my settings
I disabled all the plugins and still nothing
but your question on the sp/wp admin had me thinking, when we used buddypress and bbpress some reason it changed my nickname to homesteading-board, so when someone tried mentioning me in sp it would autofill with that but display as kvr on the forum, I checked the nickname settings through sp and wp and they both showed as kvr, so I poked around the database under the wp user table and sure enough it showed the homesteading-board in it so I changed it to kvr, the mentions worked fine after that, would that have anything to do with it?
Under my wp user profile this is what shows.
bbp_keymaster, SPF Manage Options, SPF Manage Forums, SPF Manage User Groups, SPF Manage Permissions, SPF Manage Components, SPF Manage Admins, SPF Manage Users, SPF Manage Profiles, SPF Manage Toolbox, SPF Manage Plugins, SPF Manage Themes, SPF Manage Integration, SPF Manage PM, SPF Manage Polls
I don’t even have keymaster as a role anymore, I had to do this just to remove the roles from bbpress that they don’t when it is deleted.
https://codex.wordpress.org/Function_Reference/remove_role
Man I regret installing that plugin.