I use / used a Sennheiser USB Headset ( no model number on them) for comms and skype but since "upgrading!" to 10.14.5 the headset no longer work . What did they do and how can I get around it without forking out for new headsets , as they still work fine on other USB equipment ? There not that old maybe 4 years ? So much wastage ..... What did they do and how can i get around it ?