I too have a similar experience since going to v1.8.x - using a PS4 pad wirelessly works in ES or Kodi fine yet when loading an emulator it shows Retroarch is connected to wireless on on port 0 yet then no response to move/start/exit game.
It did work seamlessly in 1.65 yet I have a generic pad for Kodi so shall try updating the retroarch config
I checked, and 1.8.5 retoarch did not have xinput or dinput file in autoconfig folder
I copied retroarch xinput & dinput file of PC version
Now, it is control by only use keyboard and ps4 pad together but it is not good
ps4 pad usb connection is incomplete, it work only after ps4 pad usb connetor out and in at snes screen
Do i have to buy a generic game pad?
I'm so sorry, but let me give you an easy way
thank you