Unsure midi is working

I have a KX88. The midi out is connected to the midi in of a UA-25EX which has a USB into my iMac. Since moving home and starting to use Garage Band the midi doesn’t appear to be working. Previously it worked perfectly using Logic; which is no longer installed on my iMac. Im unsure whether Garage Band has a hidden setting I can’t find or whether damp might have got into the keyboard when it was in storage. Really hope not! The KX88 powers up and displays as normal so am hopeful the midi is still working. Any advise would be greatly appreciated. Thanks!