fn and volume buttons won't work on mac

[dan sullivan 0]

Hi. Faithful user and evangelist. I just added a Mac Mini with Samsung monitor to run alongside my IMac. Mouse and keyboard work great, except for using the fn key (twice) to activate voice dictation and the volume up/down buttons. The buttons work as expected on the regular keyboard. 2009 iMac (El Capitan, runs well) Server (wireless mac keyboard) 2015 Mac Mini (El Capitan) Client (hard wired mac keyboard) I have a workaround, but it means having the 2nd keyboard laying around and I like my tidy single keyboard setup. Thank you in advance!