I’ve been using my Windows keyboard with my Mac mini for two months now, but something strange happened. Even I set up the modifier keys in the settings, the ‘fn E’ keys is not working. Any ideas on how to fix this?

I’ve been using my Windows keyboard with my Mac mini for two months now, but something strange happened. Even I set up the modifier keys in the settings, the ‘fn E’ keys is not working. Any ideas on how to fix this?