Hi orschiro,
Thanks for reaching out in Apple Support Communities. I understand that you're unable to use the F8 key to play or pause music and this issue started recently. I can see why you'd reach out about this; I'd like to help. Take a look at these steps first:
If some keys on your keyboard work and others don't, try these steps.
You might have set an option that changes how your keyboard operates. Choose Apple () menu > System Preferences, and then try these tips:
- In the Accessibility pane, click Speech in the left side. If "Speak selected text when the key is pressed" is selected, deselect it or click Change Key to select another key.
- In the Accessibility pane, click Keyboard. Make sure Enable Slow Keys is turned off. If it's on, you have to hold down a key longer than usual before it's recognized.
- In the Accessibility pane, click Mouse & Trackpad. Make sure Enable Mouse Keys is off. If it's on, pressing keys in the numeric keypad moves the pointer instead of entering numbers.
- In the Keyboard pane, click Input Sources. Make sure that the correct keyboard layout is selected.
You can also see your keyboard's current layout on your Mac's display to make sure that you're using the correct layout:
- In System Preferences, click Keyboard, then select "Show keyboard and emoji viewers in menu bar."
- Choose the keyboard icon in your menu bar, then choose Show Keyboard Viewer. You'll see a graphical representation of your keyboard that highlights the corresponding keys you press on your keyboard."
If your Apple keyboard doesn't work
I'd also suggest using these steps to clean the keyboard: How to clean the keyboard of your MacBook or MacBook Pro
If the behavior continues, try resetting the System Management Controller then test the keyboard again: How to reset the SMC of your Mac
Let me know what you find.
Best Regards.