Fn + f4 keys not working

Hello.
I have been using deepin for some time, I have installed version 20.8 and everything seems to work fine on my dell Latitude 5480 laptop except the "fn+F4" keys, these keys are used to activate and deactivate the microphone, which is very useful for video calls, but with version 20.8 they do not work, it is worth mentioning that I have installed deepin with kernel 15 and 18, and it does not work in either of them. With kernel 5.10 it worked fine. I clarify that "fn" works well with the other function keys, only with f4 it does not work, and I have checked the keyboard and it does not present physical damage, f4 key works fine. Can you help me solve this problem?